METAR Weather Observations

Airport weather reports for any ICAO station, as clean JSON. Give station codes (KORD, KJFK, EGLL, RJTT) or US coordinates, and get one row per METAR or SPECI report over the last 1 to 720 hours: temperature and dew point (F and C), wind direction, speed and gusts, visibility, ceiling, altimeter, flight category (VFR, MVFR, IFR, LIFR), the 6-hour and 24-hour max and min groups, hourly precipitation, present weather and the raw METAR exactly as published.

Or set output to daily-summary for one row per station per local day with the high, the low and when each happened.

$1.00 per 1,000 rows. No start fee. No API key, no browser, no proxy.

Where the data comes from

• Hours 1 to 672 (28 days): NOAA's Aviation Weather Center, aviationweather.gov, routine and special reports.
• Hours 673 to 720: the Iowa State University ASOS/AWOS archive (Iowa Environmental Mesonet).
• FAA identifiers with a digit (57C): the Iowa State archive, for the whole range.

A station that aviationweather.gov does not answer for is looked up in the Iowa State archive instead. US coordinates resolve to the nearest NWS observation station through api.weather.gov.

Every request goes to these public services directly, paced under their published limits: 100 requests a minute for aviationweather.gov and one request a second for the Iowa State archive (both read 2026-10-04).

Input

{
  "stationIds": ["KORD", "KJFK", "EGLL"],
  "hoursBack": 24
}

• stationIds: ICAO codes. 3-letter US codes get the K prefix (ORD becomes KORD). Commas or spaces inside one item split it. Up to 200 per run. Empty, with no coordinates: KORD.
• latLon: optional US points, as {"lat": 41.97, "lon": -87.9} objects or [41.97, -87.9] pairs. Each becomes its nearest NWS station.
• hoursBack: 1 to 720. Default 24.
• output: observations (default) or daily-summary.
• dateFrom, dateTo: daily summary only. Station-local days, YYYY-MM-DD, today or yesterday. At most 366 days.
• fields: optional. Keep only these fields; station_id and utc_time are always kept.

stationIds, latLon, output, dateFrom, dateTo, hoursBack and fields are the names other METAR Actors on the Store use, and ids and hours are read too, so an existing input usually runs here unchanged.

Output: observations

A real row from a run on 2026-10-04 ({"stationIds": ["KORD"]}):

{
  "station_id": "KORD",
  "station_name": "Chicago/O'Hare Intl, IL, US",
  "lat": 41.9602,
  "lon": -87.9316,
  "utc_time": "2026-10-04T20:51:00Z",
  "temp_f": 72.0,
  "dewpoint_f": 43.0,
  "wind_dir": 310.0,
  "wind_speed_kt": 8.0,
  "ceiling_ft": null,
  "visibility_sm": 10.0,
  "flight_category": "VFR",
  "metar_raw": "METAR KORD 042051Z 31008KT 10SM FEW300 22/06 A3014 RMK AO2 SLP203 T02220061 56005 $",
  "source": "aviationweather.gov",
  "obs_time": 1791147060,
  "report_type": "METAR",
  "temp_c": 22.2,
  "dewpoint_c": 6.1,
  "wind_gust_kt": null,
  "altimeter_hpa": 1020.7,
  "max_temp_6h_f": null,
  "min_temp_6h_f": null,
  "max_temp_24h_f": null,
  "min_temp_24h_f": null,
  "precip_in": null,
  "wx": null
}

• Temperatures come from the report's T-group (tenths of a degree C) when it has one, else from its whole-degree group. Both sources are read the same way, so the same report gives the same numbers.
• wind_dir is null for variable wind (VRB).
• ceiling_ft is the lowest broken or overcast layer, or the vertical visibility; null means no ceiling.
• visibility_sm: "10SM" and "10+" read as 10.0; 9999 metres reads as 6.0 from aviationweather.gov and 6.21 from the archive.
• precip_in is the hourly Prrrr group; a trace (P0000) is 0.0.
• report_type is METAR (routine) or SPECI (special). For archive rows it is the archive's own classification.
• source is aviationweather.gov or mesonet-asos-archive. Archive rows have station_name only when the same run also read the station from aviationweather.gov.

Output: daily summary

{"stationIds": ["KNYC", "EGLL"], "output": "daily-summary",
 "dateFrom": "2026-10-01", "dateTo": "2026-10-03"}

One row per station per station-local calendar day. Two sources, named in source:

• nws_cli: the NWS Daily Climate Report, read through the Iowa State Mesonet, for US stations that issue one. Whole degrees F, with precipitation, snowfall, the 1991-2020 normals and the records. The NWS prints times in local standard time; high_time and low_time are converted to UTC. A report issued before the day ended is marked complete: false.
• metar_derived: everywhere else, and any day with no climate report: the highest and lowest temperature among that local day's reports from the Iowa State archive, with obs_count. complete is false while the day is still running or when the reports have a hole longer than 3 hours; note says which.

A real row from a run on 2026-10-04:

{
  "record_type": "daily_summary",
  "station_id": "KNYC",
  "station_name": "NEW YORK CITY",
  "date": "2026-10-01",
  "timezone": "America/New_York",
  "source": "nws_cli",
  "high_f": 76.0,
  "high_c": 24.4,
  "high_time": "2026-10-01T18:03:00Z",
  "low_f": 65.0,
  "low_c": 18.3,
  "low_time": "2026-10-01T05:15:00Z",
  "precipitation_in": 0.0,
  "precipitation_trace": false,
  "snowfall_in": 0.0,
  "snowfall_trace": false,
  "high_normal_f": 70.0,
  "high_record_f": 88.0,
  "low_normal_f": 57.0,
  "low_record_f": 36.0,
  "precipitation_normal_in": 0.14,
  "obs_count": null,
  "complete": true,
  "note": null,
  "product_id": "202610020705-KOKX-CDUS41-CLINYC",
  "source_url": "https://mesonet.agron.iastate.edu/api/1/nwstext/202610020705-KOKX-CDUS41-CLINYC"
}

The highest hourly report is not always the day's true high: the peak can fall between reports. The climate report's high is the official one where it exists.

Price

Pay per event: $1.00 per 1,000 rows in the dataset, nothing per run. A US airport reports about 24 to 34 times a day, many airports abroad every 30 minutes, and some automated US stations every 20 minutes, so:

Run	Rows	Cost
KORD, 24 hours (2026-10-04)	24	about $0.02
KORD, 700 hours	about 890	about $0.89
EGLL, 700 hours	about 1,400	about $1.40
3 stations, 7 days, daily summary	21	about $0.02

Set Maximum cost per run to cap a run; it stops there and keeps what it returned. fields makes rows smaller, not cheaper.

Limits

• 720 hours (30 days) of reports; 366 days of daily summaries.
• 200 stations and 50 points per run.
• Coordinates work in the US only. Elsewhere, give the ICAO code.
• A station that is unknown, or silent for the whole range, returns no rows and is named in the run's status message. Nothing is charged for it.
• aviationweather.gov holds about 30 days. The Iowa State archive holds older years too, but this Actor reads at most 30 days of reports per run.

What it will not do

• No forecasts (TAF), no radar, no model data. Observations only.
• No estimates: a missing value is null, never filled in.
• No scraping of weather websites. Public government and university data services only.

Not affiliated with NOAA, the NWS or Iowa State University. The data is theirs; please credit "NOAA Aviation Weather Center" and "Iowa Environmental Mesonet, Iowa State University" where you publish it.

Changelog

• 0.1 (2026-10-04): first release.