Add NWS (National Weather Service) as a selectable data source preference

- New Settings > Data source toggle (Open-Meteo global / NWS US); NWS
  falls back to Open-Meteo when unavailable or outside its coverage.
- src/lib/api/nws.js: /points -> forecast/hourly/grid normalizer producing
  the app's shared shape, with realistic air highs (NWS reports 104 for the
  day Open-Meteo over-forecasts at 116); heat-index/feels-like falls back to
  air temp since NWS returns apparentTemperature as null here.
- NWS requires a User-Agent contact; email is a build-time Vite env
  (VITE_NWS_EMAIL), read from gitignored .env.local, never committed.
- Details view now shows which provider served the data.
- Fixes the identical UTC date-parse shift for NWS naive local times.
- Tests (8) + recorded live fixtures for Rogers County, OK.

.gitignore

@@ -21,3 +21,9 @@ dist-ssr
 *.njsproj
 *.sln
 *.sw?
+
+
+# Build-time secrets (never commit)
+.env
+.env.*
+!.env.example

src/components/SettingsDialog.svelte

@@ -61,6 +61,24 @@
     </div>
 
     <div class="settings-body">
+      <!-- Data source -->
+      <div class="settings-group">
+        <h4>Data source</h4>
+        <div class="setting-row">
+          <div class="setting-col">
+            <span>Weather provider</span>
+            <span class="setting-help">NWS is US-only; falls back to Open-Meteo if unavailable.</span>
+          </div>
+          <select
+            value={localSettings.source || 'open-meteo'}
+            onchange={(e) => localSettings.source = e.target.value}
+          >
+            <option value="open-meteo">Open-Meteo (global)</option>
+            <option value="nws">National Weather Service (US)</option>
+          </select>
+        </div>
+      </div>
+
       <!-- Units -->
       <div class="settings-group">
         <h4>Units</h4>
@@ -267,6 +285,18 @@
     border-top: 1px solid var(--color-border);
   }
 
+  .setting-col {
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+    padding-right: 12px;
+  }
+
+  .setting-help {
+    font-size: 0.72rem;
+    color: var(--color-text-muted);
+  }
+
   .setting-row span {
     color: var(--color-text);
   }

src/components/WeatherDetail.svelte

@@ -174,6 +174,10 @@
 
     <!-- Time info -->
     <div class="time-info card mt-3">
+      <div class="time-row">
+        <span>Data source</span>
+        <span class="detail-value">{data?._source === 'nws' ? 'NWS (National Weather Service)' : 'Open-Meteo'}</span>
+      </div>
       <div class="time-row">
         <span>Local time</span>
         <span class="detail-value">{data.timezone || '--'}</span>

src/lib/api/nws.js

@@ -0,0 +1,235 @@
+/**
+ * NWS API (api.weather.gov) client + normalizer.
+ *
+ * Converts the National Weather Service forecast into the same flat shape the
+ * app's components expect (an Open-Meteo-style response), so the rest of the
+ * UI needs no per-source branches. US-only: NWS is queried via
+ * /points/{lat},{lon} which resolves to the nearest gridpoint forecast.
+ */
+
+import { NWS_USER_AGENT } from '../config.js'
+
+const API = 'https://api.weather.gov'
+
+
+async function jsonGet(url) {
+  if (!url) throw new Error('Missing NWS forecast URL')
+  const res = await fetch(url, {
+    headers: {
+      'User-Agent': NWS_USER_AGENT,
+      'Accept': 'application/geo+json',
+    },
+  })
+  if (!res.ok) throw new Error(`NWS API error: ${res.status} ${res.statusText}`)
+  return res.json()
+}
+
+// --- pure helpers (also unit-tested) ---
+
+function ftoC(f) {
+  return (f - 32) * 5 / 9
+}
+function mphToKmh(mph) {
+  return mph * 1.609344
+}
+
+/** Normalize a value to the requested unit. */
+function temp(v, units) {
+  return units === 'imperial' ? v : ftoC(v)
+}
+function speed(v, units) {
+  return units === 'imperial' ? v : mphToKmh(v)
+}
+
+const CARD = ['N','NNE','NE','ENE','E','ESE','SE','SSE','S','SSW','SW','WSW','W','WNW','NW','NNW']
+export function compassToDeg(dir) {
+  if (dir == null) return null
+  const s = String(dir).trim().toUpperCase()
+  const i = CARD.indexOf(s)
+  return i >= 0 ? i * 22.5 : null
+}
+
+/** Extract the max wind speed (mph) from strings like "5 to 10 mph" or "12 mph". */
+export function parseWind(s) {
+  if (s == null) return null
+  const nums = String(s).match(/\d+(\.\d+)?/g)
+  if (!nums || !nums.length) return null
+  return Math.max(...nums.map(Number))
+}
+
+/** Map an NWS shortForecast string to a WMO code for icons/severity. */
+export function shortForecastToWmo(text) {
+  const t = (text || '').toLowerCase()
+  if (/thunderstorm|tstm|severe thunder/.test(t)) return /\bsevere\b/.test(t) ? 96 : 95
+  if (/freez|x-ice|ice pellets/.test(t) && /rain|drizzle|shower/.test(t)) return 66
+  if (/snow|blizzard|flurr|sleet|snow shower/.test(t)) return /heavy|blizzard/.test(t) ? 75 : 71
+  if (/freez|ice/.test(t)) return 66
+  if (/rain|shower|drizzle|sprinkl/.test(t)) return /heavy|strong|torrential/.test(t) ? 65 : /slight|isolated|scattered/.test(t) ? 61 : 63
+  if (/fog|haze|smoke|brume/.test(t)) return 45
+  if (/partly (cloudy|sunny)/.test(t)) return 2
+  if (/overcast|covering|cloudy/.test(t)) return 3
+  if (/sunny|clear|fair/.test(t)) return /most|mostly/.test(t) ? 2 : 0
+  return 1
+}
+
+function wmoRank(code) {
+  if (code >= 95) return 8
+  if (code >= 80 && code <= 86) return 7
+  if (code >= 65 && code <= 82) return 6
+  if (code >= 71 && code <= 77) return 5
+  if (code >= 45 && code <= 48) return 4
+  if (code <= 3) return 1
+  return 2
+}
+
+/** Local calendar date "YYYY-MM-DD" for an ISO timestamp in a timezone. */
+export function dateKey(iso, tz) {
+  const p = new Intl.DateTimeFormat('en-CA', {
+    timeZone: tz, year: 'numeric', month: '2-digit', day: '2-digit',
+  }).formatToParts(new Date(iso))
+  const P = Object.fromEntries(p.map((x) => [x.type, x.value]))
+  return `${P.year}-${P.month}-${P.day}`
+}
+
+/** Local naive wall-clock "YYYY-MM-DDTHH:MM" (no offset) for an ISO timestamp. */
+export function localTimeString(iso, tz) {
+  const p = new Intl.DateTimeFormat('en-CA', {
+    timeZone: tz, year: 'numeric', month: '2-digit', day: '2-digit',
+    hour: '2-digit', minute: '2-digit', hour12: false,
+  }).formatToParts(new Date(iso))
+  const P = Object.fromEntries(p.map((x) => [x.type, x.value]))
+  const h = P.hour === '24' ? '00' : String(P.hour).padStart(2, '0')
+  return `${P.year}-${P.month}-${P.day}T${h}:${String(P.minute).padStart(2, '0')}`
+}
+
+function prob(period) {
+  const v = period?.probabilityOfPrecipitation?.value
+  return v == null ? 0 : v
+}
+
+/** Build daily arrays from NWS forecast periods (14 periods ~ 7 days). */
+function buildDaily(periods, tz, units) {
+  const byDate = new Map()
+  for (const pd of periods) {
+    const key = dateKey(pd.startTime, tz)
+    if (!byDate.has(key)) {
+      byDate.set(key, { highs: [], lows: [], precip: [], codes: [], winds: [] })
+    }
+    const d = byDate.get(key)
+    const t = pd.temperature
+    if (t != null) {
+      const c = temp(t, units)
+      if (pd.isDaytime) d.highs.push(c)
+      else d.lows.push(c)
+    }
+    d.precip.push(prob(pd))
+    d.codes.push(shortForecastToWmo(pd.shortForecast))
+    const ws = parseWind(pd.windSpeed)
+    if (ws != null) d.winds.push(ws)
+  }
+
+  const dates = [...byDate.keys()].sort()
+  const time = [], temperature_2m_max = [], temperature_2m_min = []
+  const precipitation_probability_max = [], weather_code = [], wind_speed_10m_max = []
+  for (const key of dates) {
+    const d = byDate.get(key)
+    const high = d.highs.length ? Math.max(...d.highs) : (d.lows.length ? Math.max(...d.lows) : null)
+    const low = d.lows.length ? Math.min(...d.lows) : (d.highs.length ? Math.min(...d.highs) : null)
+    time.push(key)
+    temperature_2m_max.push(high)
+    temperature_2m_min.push(low)
+    precipitation_probability_max.push(Math.max(...d.precip, 0))
+    weather_code.push(d.codes.reduce((a, b) => (wmoRank(b) > wmoRank(a) ? b : a)))
+    wind_speed_10m_max.push(speed(Math.max(...d.winds, 0), units))
+  }
+  return { time, temperature_2m_max, temperature_2m_min, precipitation_probability_max, weather_code, wind_speed_10m_max }
+}
+
+/**
+ * Normalize raw NWS responses into the app's shared shape.
+ * @param {object} src - { points, forecast, hourly, grid, timeZone, units }
+ */
+export function normalizeNWS(src) {
+  const { points, forecast, hourly, grid, timeZone, units } = src
+  const tz = timeZone || 'UTC'
+  const hourlyPeriods = hourly?.properties?.periods || []
+  const forecastPeriods = forecast?.properties?.periods || []
+
+  // Current = first hourly period (most recent).
+  const cur = hourlyPeriods[0]
+  let current = null
+  if (cur) {
+    const ws = parseWind(cur.windSpeed)
+    const apparent = cur.apparentTemperature != null ? temp(cur.apparentTemperature, units) : temp(cur.temperature, units)
+    current = {
+      time: localTimeString(cur.startTime, tz),
+      temperature_2m: temp(cur.temperature, units),
+      apparent_temperature: apparent,
+      relative_humidity_2m: cur.relativeHumidity?.value ?? null,
+      weather_code: shortForecastToWmo(cur.shortForecast),
+      wind_speed_10m: ws != null ? speed(ws, units) : null,
+      wind_direction_10m: compassToDeg(cur.windDirection),
+      wind_gusts_10m: null,
+      pressure_msl: null,
+      uv_index: null,
+      is_day: cur.isDaytime ? 1 : 0,
+    }
+  }
+
+  // ---- hourly (all returned periods; the UI slices the next 24) ----
+  const time = [], temperature_2m = [], precipitation_probability = [], weather_code = [], wind_speed_10m = []
+  for (const pd of hourlyPeriods) {
+    time.push(localTimeString(pd.startTime, tz))
+    temperature_2m.push(temp(pd.temperature, units))
+    precipitation_probability.push(prob(pd))
+    weather_code.push(shortForecastToWmo(pd.shortForecast))
+    const ws = parseWind(pd.windSpeed)
+    wind_speed_10m.push(ws != null ? speed(ws, units) : null)
+  }
+
+  // ---- daily ----
+  const daily = buildDaily(forecastPeriods, tz, units)
+
+  // ---- sunrise / sunset (today only, from gridpoints buildSet) ----
+  const rise = grid?.properties?.riseSet
+  if (rise) {
+    const sr = rise.sunrise?.[0]?.time
+    const ss = rise.sunset?.[0]?.time
+    if (sr) daily.sunrise = [localTimeString(sr, tz)]
+    if (ss) daily.sunset = [localTimeString(ss, tz)]
+  }
+
+  const elevation = grid?.properties?.elevation?.value
+
+  return {
+    _source: 'nws',
+    timezone: tz,
+    utc_offset_seconds: null,
+    elevation,
+    current,
+    hourly: { time, temperature_2m, precipitation_probability, weather_code, wind_speed_10m },
+    daily,
+  }
+}
+
+/**
+ * Fetch + normalize the NWS forecast for a latitude/longitude.
+ * US-only; throws for non-US points (NWS returns 404 outside its domain).
+ * @param {number} lat
+ * @param {number} lon
+ * @param {string} [units='imperial'] - 'imperial' or 'metric'
+ */
+export async function fetchForecastNWS(lat, lon, units = 'imperial') {
+  const pointsUrl = `${API}/points/${lat},${lon}`
+  const points = await jsonGet(pointsUrl)
+  const props = points.properties || {}
+  const tz = props.timeZone || 'America/New_York'
+
+  const [forecast, hourly, grid] = await Promise.all([
+    jsonGet(props.forecast),
+    jsonGet(props.forecastHourly),
+    jsonGet(props.forecastGridData),
+  ])
+
+  return normalizeNWS({ points, forecast, hourly, grid, timeZone: tz, units })
+}

src/lib/config.js

@@ -0,0 +1,19 @@
+/**
+ * Build-time configuration.
+ *
+ * Values here are read from Vite environment variables (`import.meta.env`),
+ * inlined at build time - so the deployed bundle carries whatever is set in
+ * the local env file when you run `npm run build`. Nothing secret is committed
+ * to the repo; set it in a local (gitignored) .env.local:
+ *
+ *   VITE_NWS_EMAIL=you@example.com
+ *
+ * NWS (api.weather.gov) requires a descriptive User-Agent with a contact
+ * address. If not configured we still send an app identifier, but a real
+ * contact email is recommended for stable access.
+ */
+const NWS_EMAIL = import.meta.env.VITE_NWS_EMAIL || ''
+
+export const NWS_USER_AGENT = NWS_EMAIL
+  ? `WeatherLens/0.1 (${NWS_EMAIL})`
+  : 'WeatherLens/0.1 (weather app; contact not configured)'

src/lib/storage/db.js

@@ -123,6 +123,7 @@ export async function clearAllLocations() {
 
 const DEFAULT_SETTINGS = {
   units: 'metric',
+  source: 'open-meteo',
   alertsEnabled: true,
   alertThresholds: {
     precip: 70,

src/lib/stores/app.svelte.js

@@ -4,6 +4,7 @@
 
 import { getLocations, loadSettings } from '../storage/db.js'
 import { fetchForecast } from '../api/weather.js'
+import { fetchForecastNWS } from '../api/nws.js'
 
 export class AppStore {
   // Location state
@@ -31,6 +32,7 @@ export class AppStore {
   // Settings
   settings = $state({
     units: 'metric',
+    source: 'open-meteo',
     alertsEnabled: true,
     alertThresholds: {
       precip: 70,
@@ -108,7 +110,21 @@ export class AppStore {
     this.error = ''
 
     try {
-      const data = await fetchForecast(location.lat, location.lon, this.settings.units)
+      const units = this.settings.units
+      const source = this.settings.source || 'open-meteo'
+      let data
+      if (source === 'nws') {
+        try {
+          data = await fetchForecastNWS(location.lat, location.lon, units)
+        } catch (nwsErr) {
+          // NWS is US-only and can be unavailable — fall back to Open-Meteo
+          // so the app keeps working rather than breaking.
+          console.warn('NWS unavailable, falling back to Open-Meteo:', nwsErr.message)
+          data = await fetchForecast(location.lat, location.lon, units)
+        }
+      } else {
+        data = await fetchForecast(location.lat, location.lon, units)
+      }
       this.forecastData = data
 
       // Update the location name if we got a timezone abbreviation

tests/fixtures/nws/forecast.json

@@ -0,0 +1,319 @@
+{
+    "@context": [
+        "https://geojson.org/geojson-ld/geojson-context.jsonld",
+        {
+            "@version": "1.1",
+            "wx": "https://api.weather.gov/ontology#",
+            "geo": "http://www.opengis.net/ont/geosparql#",
+            "unit": "http://codes.wmo.int/common/unit/",
+            "@vocab": "https://api.weather.gov/ontology#"
+        }
+    ],
+    "type": "Feature",
+    "geometry": {
+        "type": "Polygon",
+        "coordinates": [
+            [
+                [
+                    -95.7922,
+                    36.3555
+                ],
+                [
+                    -95.7924,
+                    36.3779
+                ],
+                [
+                    -95.8201,
+                    36.3778
+                ],
+                [
+                    -95.82,
+                    36.3554
+                ],
+                [
+                    -95.7922,
+                    36.3555
+                ]
+            ]
+        ]
+    },
+    "properties": {
+        "units": "us",
+        "forecastGenerator": "BaselineForecastGenerator",
+        "generatedAt": "2026-08-16T20:09:21+00:00",
+        "updateTime": "2026-08-16T19:50:51+00:00",
+        "validTimes": "2026-08-16T17:00:00+00:00/P7DT8H",
+        "elevation": {
+            "unitCode": "wmoUnit:m",
+            "value": 196.9008
+        },
+        "periods": [
+            {
+                "number": 1,
+                "name": "This Afternoon",
+                "startTime": "2026-08-16T15:00:00-05:00",
+                "endTime": "2026-08-16T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 103,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 17
+                },
+                "windSpeed": "10 mph",
+                "windDirection": "W",
+                "icon": "https://api.weather.gov/icons/land/day/tsra_hi,20?size=medium",
+                "shortForecast": "Slight Chance Showers And Thunderstorms",
+                "detailedForecast": "A slight chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 103. Heat index values as high as 112. West wind around 10 mph. Chance of precipitation is 20%."
+            },
+            {
+                "number": 2,
+                "name": "Tonight",
+                "startTime": "2026-08-16T18:00:00-05:00",
+                "endTime": "2026-08-17T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 75,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 24
+                },
+                "windSpeed": "5 mph",
+                "windDirection": "N",
+                "icon": "https://api.weather.gov/icons/land/night/tsra_hi,20?size=medium",
+                "shortForecast": "Slight Chance Showers And Thunderstorms",
+                "detailedForecast": "A slight chance of showers and thunderstorms. Partly cloudy, with a low around 75. Heat index values as high as 110. North wind around 5 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible."
+            },
+            {
+                "number": 3,
+                "name": "Monday",
+                "startTime": "2026-08-17T06:00:00-05:00",
+                "endTime": "2026-08-17T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 94,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 24
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "N",
+                "icon": "https://api.weather.gov/icons/land/day/tsra_hi,20?size=medium",
+                "shortForecast": "Slight Chance Showers And Thunderstorms",
+                "detailedForecast": "A slight chance of showers and thunderstorms. Mostly sunny, with a high near 94. Heat index values as high as 105. North wind 5 to 10 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible."
+            },
+            {
+                "number": 4,
+                "name": "Monday Night",
+                "startTime": "2026-08-17T18:00:00-05:00",
+                "endTime": "2026-08-18T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 73,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 16
+                },
+                "windSpeed": "0 to 5 mph",
+                "windDirection": "NE",
+                "icon": "https://api.weather.gov/icons/land/night/tsra_hi,20/few?size=medium",
+                "shortForecast": "Slight Chance Showers And Thunderstorms then Mostly Clear",
+                "detailedForecast": "A slight chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 73. Heat index values as high as 103. Northeast wind 0 to 5 mph. Chance of precipitation is 20%."
+            },
+            {
+                "number": 5,
+                "name": "Tuesday",
+                "startTime": "2026-08-18T06:00:00-05:00",
+                "endTime": "2026-08-18T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 101,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 11
+                },
+                "windSpeed": "0 to 5 mph",
+                "windDirection": "SE",
+                "icon": "https://api.weather.gov/icons/land/day/hot?size=medium",
+                "shortForecast": "Sunny",
+                "detailedForecast": "Sunny, with a high near 101. Southeast wind 0 to 5 mph."
+            },
+            {
+                "number": 6,
+                "name": "Tuesday Night",
+                "startTime": "2026-08-18T18:00:00-05:00",
+                "endTime": "2026-08-19T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 79,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 1
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "S",
+                "icon": "https://api.weather.gov/icons/land/night/few?size=medium",
+                "shortForecast": "Mostly Clear",
+                "detailedForecast": "Mostly clear, with a low around 79. South wind 5 to 10 mph."
+            },
+            {
+                "number": 7,
+                "name": "Wednesday",
+                "startTime": "2026-08-19T06:00:00-05:00",
+                "endTime": "2026-08-19T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 104,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 1
+                },
+                "windSpeed": "10 mph",
+                "windDirection": "SW",
+                "icon": "https://api.weather.gov/icons/land/day/hot?size=medium",
+                "shortForecast": "Sunny",
+                "detailedForecast": "Sunny, with a high near 104. Southwest wind around 10 mph."
+            },
+            {
+                "number": 8,
+                "name": "Wednesday Night",
+                "startTime": "2026-08-19T18:00:00-05:00",
+                "endTime": "2026-08-20T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 76,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 12
+                },
+                "windSpeed": "10 to 15 mph",
+                "windDirection": "S",
+                "icon": "https://api.weather.gov/icons/land/night/few?size=medium",
+                "shortForecast": "Mostly Clear",
+                "detailedForecast": "Mostly clear, with a low around 76. South wind 10 to 15 mph, with gusts as high as 20 mph."
+            },
+            {
+                "number": 9,
+                "name": "Thursday",
+                "startTime": "2026-08-20T06:00:00-05:00",
+                "endTime": "2026-08-20T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 98,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 12
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "NE",
+                "icon": "https://api.weather.gov/icons/land/day/sct?size=medium",
+                "shortForecast": "Mostly Sunny",
+                "detailedForecast": "Mostly sunny, with a high near 98. Northeast wind 5 to 10 mph."
+            },
+            {
+                "number": 10,
+                "name": "Thursday Night",
+                "startTime": "2026-08-20T18:00:00-05:00",
+                "endTime": "2026-08-21T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 72,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 7
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "NE",
+                "icon": "https://api.weather.gov/icons/land/night/few?size=medium",
+                "shortForecast": "Mostly Clear",
+                "detailedForecast": "Mostly clear, with a low around 72. Northeast wind 5 to 10 mph."
+            },
+            {
+                "number": 11,
+                "name": "Friday",
+                "startTime": "2026-08-21T06:00:00-05:00",
+                "endTime": "2026-08-21T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 97,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 7
+                },
+                "windSpeed": "5 mph",
+                "windDirection": "NE",
+                "icon": "https://api.weather.gov/icons/land/day/few?size=medium",
+                "shortForecast": "Sunny",
+                "detailedForecast": "Sunny, with a high near 97. Northeast wind around 5 mph."
+            },
+            {
+                "number": 12,
+                "name": "Friday Night",
+                "startTime": "2026-08-21T18:00:00-05:00",
+                "endTime": "2026-08-22T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 72,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 3
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "NE",
+                "icon": "https://api.weather.gov/icons/land/night/few?size=medium",
+                "shortForecast": "Mostly Clear",
+                "detailedForecast": "Mostly clear, with a low around 72. Northeast wind 5 to 10 mph."
+            },
+            {
+                "number": 13,
+                "name": "Saturday",
+                "startTime": "2026-08-22T06:00:00-05:00",
+                "endTime": "2026-08-22T18:00:00-05:00",
+                "isDaytime": true,
+                "temperature": 99,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 4
+                },
+                "windSpeed": "5 mph",
+                "windDirection": "E",
+                "icon": "https://api.weather.gov/icons/land/day/few?size=medium",
+                "shortForecast": "Sunny",
+                "detailedForecast": "Sunny, with a high near 99. East wind around 5 mph."
+            },
+            {
+                "number": 14,
+                "name": "Saturday Night",
+                "startTime": "2026-08-22T18:00:00-05:00",
+                "endTime": "2026-08-23T06:00:00-05:00",
+                "isDaytime": false,
+                "temperature": 73,
+                "temperatureUnit": "F",
+                "temperatureTrend": null,
+                "probabilityOfPrecipitation": {
+                    "unitCode": "wmoUnit:percent",
+                    "value": 5
+                },
+                "windSpeed": "5 to 10 mph",
+                "windDirection": "E",
+                "icon": "https://api.weather.gov/icons/land/night/few?size=medium",
+                "shortForecast": "Mostly Clear",
+                "detailedForecast": "Mostly clear, with a low around 73. East wind 5 to 10 mph."
+            }
+        ]
+    }
+}

tests/fixtures/nws/grid.json

@@ -0,0 +1 @@
+{"properties": {"elevation": {"value": 196.9008}}}

tests/fixtures/nws/points.json

@@ -0,0 +1,112 @@
+{
+    "@context": [
+        "https://geojson.org/geojson-ld/geojson-context.jsonld",
+        {
+            "@version": "1.1",
+            "wx": "https://api.weather.gov/ontology#",
+            "s": "https://schema.org/",
+            "geo": "http://www.opengis.net/ont/geosparql#",
+            "unit": "http://codes.wmo.int/common/unit/",
+            "@vocab": "https://api.weather.gov/ontology#",
+            "geometry": {
+                "@id": "s:GeoCoordinates",
+                "@type": "geo:wktLiteral"
+            },
+            "city": "s:addressLocality",
+            "state": "s:addressRegion",
+            "distance": {
+                "@id": "s:Distance",
+                "@type": "s:QuantitativeValue"
+            },
+            "bearing": {
+                "@type": "s:QuantitativeValue"
+            },
+            "value": {
+                "@id": "s:value"
+            },
+            "unitCode": {
+                "@id": "s:unitCode",
+                "@type": "@id"
+            },
+            "forecastOffice": {
+                "@type": "@id"
+            },
+            "forecastGridData": {
+                "@type": "@id"
+            },
+            "publicZone": {
+                "@type": "@id"
+            },
+            "county": {
+                "@type": "@id"
+            }
+        }
+    ],
+    "id": "https://api.weather.gov/points/36.3567,-95.8146",
+    "type": "Feature",
+    "geometry": {
+        "type": "Point",
+        "coordinates": [
+            -95.8146,
+            36.3567
+        ]
+    },
+    "properties": {
+        "@id": "https://api.weather.gov/points/36.3567,-95.8146",
+        "@type": "wx:Point",
+        "cwa": "TSA",
+        "type": "land",
+        "forecastOffice": "https://api.weather.gov/offices/TSA",
+        "gridId": "TSA",
+        "gridX": 48,
+        "gridY": 114,
+        "forecast": "https://api.weather.gov/gridpoints/TSA/48,114/forecast",
+        "forecastHourly": "https://api.weather.gov/gridpoints/TSA/48,114/forecast/hourly",
+        "forecastGridData": "https://api.weather.gov/gridpoints/TSA/48,114",
+        "observationStations": "https://api.weather.gov/gridpoints/TSA/48,114/stations",
+        "relativeLocation": {
+            "type": "Feature",
+            "geometry": {
+                "type": "Point",
+                "coordinates": [
+                    -95.8617563,
+                    36.3692625
+                ]
+            },
+            "properties": {
+                "city": "Collinsville",
+                "state": "OK",
+                "distance": {
+                    "unitCode": "wmoUnit:m",
+                    "value": 0
+                },
+                "bearing": {
+                    "unitCode": "wmoUnit:degree_(angle)",
+                    "value": 0
+                }
+            }
+        },
+        "forecastZone": "https://api.weather.gov/zones/forecast/OKZ060",
+        "county": "https://api.weather.gov/zones/county/OKC143",
+        "fireWeatherZone": "https://api.weather.gov/zones/fire/OKZ060",
+        "timeZone": "America/Chicago",
+        "radarStation": "KINX",
+        "astronomicalData": {
+            "sunrise": "2026-08-16T06:42:13-05:00",
+            "sunset": "2026-08-16T20:12:46-05:00",
+            "transit": "2026-08-16T13:27:29-05:00",
+            "civilTwilightBegin": "2026-08-16T06:15:02-05:00",
+            "civilTwilightEnd": "2026-08-16T20:39:57-05:00",
+            "nauticalTwilightBegin": "2026-08-16T05:42:19-05:00",
+            "nauticalTwilightEnd": "2026-08-16T21:12:40-05:00",
+            "astronomicalTwilightBegin": "2026-08-16T05:07:54-05:00",
+            "astronomicalTwilightEnd": "2026-08-16T21:47:05-05:00"
+        },
+        "nwr": {
+            "transmitter": "KIH27",
+            "sameCode": "040143",
+            "areaBroadcast": "https://api.weather.gov/radio/KIH27/broadcast",
+            "pointBroadcast": "https://api.weather.gov/points/36.3567,-95.8146/radio"
+        }
+    }
+}

tests/nws.test.js

@@ -0,0 +1,87 @@
+import { describe, it, expect } from 'vitest'
+import { readFileSync } from 'node:fs'
+import path from 'node:path'
+import {
+  compassToDeg,
+  parseWind,
+  shortForecastToWmo,
+  dateKey,
+  localTimeString,
+  normalizeNWS,
+} from '../src/lib/api/nws.js'
+
+const FIX = (name) => JSON.parse(readFileSync(path.join('tests/fixtures/nws', name), 'utf8'))
+
+describe('nws helpers', () => {
+  it('shortForecastToWmo maps text to WMO codes', () => {
+    expect(shortForecastToWmo('Sunny')).toBe(0)
+    expect(shortForecastToWmo('Mostly Sunny')).toBe(2)
+    expect(shortForecastToWmo('Partly Cloudy')).toBe(2)
+    expect(shortForecastToWmo('Overcast')).toBe(3)
+    expect(shortForecastToWmo('Slight Chance Showers And Thunderstorms')).toBe(95)
+    expect(shortForecastToWmo('Heavy Rain')).toBe(65)
+    expect(shortForecastToWmo('Light Snow')).toBe(71)
+    expect(shortForecastToWmo('Areas of Fog')).toBe(45)
+  })
+
+  it('compassToDeg maps compass points to degrees', () => {
+    expect(compassToDeg('N')).toBe(0)
+    expect(compassToDeg('NE')).toBe(45)
+    expect(compassToDeg('SW')).toBe(225)
+    expect(compassToDeg('W')).toBe(270)
+    expect(compassToDeg(null)).toBeNull()
+  })
+
+  it('parseWind takes the max speed from a range string', () => {
+    expect(parseWind('5 to 10 mph')).toBe(10)
+    expect(parseWind('12 mph')).toBe(12)
+    expect(parseWind('gusts up to 20 mph')).toBe(20)
+    expect(parseWind(null)).toBeNull()
+  })
+
+  it('dateKey and localTimeString produce naive local times (no UTC shift)', () => {
+    const tz = 'America/Chicago'
+    expect(dateKey('2026-08-16T15:00:00-05:00', tz)).toBe('2026-08-16')
+    expect(localTimeString('2026-08-16T15:00:00-05:00', tz)).toBe('2026-08-16T15:00')
+    expect(localTimeString('2026-08-19T15:00:00-05:00', tz)).toMatch(/^2026-08-19T/)
+  })
+})
+
+describe('normalizeNWS (recorded live fixture for Rogers County, OK)', () => {
+  const points = FIX('points.json')
+  const forecast = FIX('forecast.json')
+  const hourly = FIX('hourly.json')
+  const grid = FIX('grid.json')
+  const timeZone = points.properties.timeZone
+
+  const data = normalizeNWS({ points, forecast, hourly, grid, timeZone, units: 'imperial' })
+
+  it('marks the source as nws', () => {
+    expect(data._source).toBe('nws')
+  })
+
+  it('normalizes air high (not heat index) for the 7-day, matching NWS values', () => {
+    // NWS daytime highs: Today 103, Mon 94, Wed 104 ... (NO 116 outlier)
+    expect(data.daily.time).toHaveLength(7)
+    expect(data.daily.temperature_2m_max[0]).toBe(103) // Today
+    expect(data.daily.temperature_2m_max[1]).toBe(94) // Monday
+    expect(data.daily.temperature_2m_max[3]).toBe(104) // Wednesday
+    expect(Math.max(...data.daily.temperature_2m_max)).toBeLessThan(115)
+    expect(data.daily.temperature_2m_min[0]).toBe(75)
+    expect(data.daily.precipitation_probability_max[0]).toBe(24)
+  })
+
+  it('builds a realistic current from the first hourly period', () => {
+    expect(data.current.temperature_2m).toBe(102)
+    expect(data.current.relative_humidity_2m).toBe(35)
+    expect(data.current.wind_direction_10m).toBe(225) // SW
+    expect(data.current.time).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}$/)
+  })
+
+  it('normalizes to metric on request', () => {
+    const m = normalizeNWS({ points, forecast, hourly, grid, timeZone, units: 'metric' })
+    expect(m.current.temperature_2m).toBeCloseTo((102 - 32) * 5 / 9, 1)
+    expect(m.daily.temperature_2m_max[0]).toBeCloseTo((103 - 32) * 5 / 9, 1)
+    expect(m.current.wind_speed_10m).toBeCloseTo(10 * 1.609344, 1)
+  })
+})