weather.us.observation

US Weather Observation

The latest surface reading from the nearest National Weather Service station, with its age in seconds and a staleness flag. The most recent measurement, not a live reading.

Example answer

Ask

What was the most recently observed temperature at these US coordinates?

GET /v1/weather/us/observation?lat=38.8977&lon=-77.0365

Eckari

{
  "station": {
    "id": "KDCA",
    "name": "Washington/Reagan National Airport, DC",
    "distance_km": 5.49
  },
  "observed_at": "2026-08-18T14:20:00.000Z",
  "age_seconds": 1007,
  "is_stale": false,
  "text_description": "Mostly Clear",
  "temperature_c": 29,
  "temperature_f": 84.2,
  "dewpoint_c": 22,
  "relative_humidity_pct": 65.98,
  "wind_speed_kmh": 12.96,
  "wind_direction_deg": 320,
  "wind_gust_kmh": null,
  "barometric_pressure_hpa": 1012.53,
  "visibility_m": 16093.44,
  "precipitation_last_hour_mm": null,
  "cloud_layers": [
    {
      "amount": {
        "code": "FEW",
        "description": "few (1-2 oktas)"
      },
      "base_m": 853.44
    }
  ]
}

Source: National Weather Service
Freshness: Near live
Price: $0.003

Version: 2.1.0
Transport: HTTP / MCP
Coverage: US

Use this when

What was the most recently observed temperature at these US coordinates?
You need measured conditions (temperature, humidity, wind, pressure, visibility) with a timestamp.
You need to know how old the observation is before acting on it.
You need the reporting station id and distance for provenance.
You need observed cloud layers or visibility for an aviation or logistics decision.

Don't use this when

You need a prediction rather than a measurement - use weather.us.forecast.
You need warnings, watches or advisories - use weather.us.alerts.
You need a guaranteed real-time reading; observations can be an hour old, so check age_seconds and is_stale.
The location is outside the United States and its territories (returns UNSUPPORTED_REGION).

If the user has asked you to inspect a specific website, page or URL, use your browsing tool instead — this capability only returns the US National Weather Service API record.

Input

latnumberrequired

Latitude in decimal degrees (WGS84). Rounded to 4 decimal places before the National Weather Service lookup.

lonnumberrequired

Longitude in decimal degrees (WGS84). Rounded to 4 decimal places before the National Weather Service lookup.

What the result means

stationobject

observed_atstring

Time the observation was taken, as reported by the station (RFC 3339 UTC). This is not the request time.

age_secondsinteger

Whole seconds between observed_at and the time this response was produced. Always inspect this before treating the reading as current.

is_staleboolean

True only when age_seconds exceeds 10800 (3 hours), which means the station has missed several reporting cycles. False does NOT mean the reading is current: most stations report every 20-60 minutes, so a reading with is_stale false can still be up to about an hour old. Read age_seconds to decide whether the observation is recent enough for your purpose. The observation is returned either way.

text_descriptionstring, null

Station's own summary phrase such as Mostly Cloudy.

temperature_cnumber, null

Air temperature in degrees Celsius (2 decimal places). Null when the station omits the value or its quality control rejected it (NWS qualityControl X = failed or Q = questionable).

Provenance

Source: National Weather Service
Freshness: Near live · read at request time, not cached
Region: US

Access

Over MCP: weather_us_observation
Over HTTP: GET https://api.eckari.com/v1/weather/us/observation
Price: $0.003 per call over x402. Account access $0.002 when that rail opens.