Coverage and models

Area

Everything covers the continental United States with a margin: longitude −125 to −66.5, latitude 24 to 49.5. Global models (GFS, ECMWF) are clipped to the same box. Requests outside it return 400 with the box in the message.

Observations (stations, gauges, radar, lightning, soundings, alerts, discussions) are nationwide within the same box. Some static layers are regional; see Static outdoor layers.

Forecast models

Slug	Model	Resolution	Runs	Horizon served	Notes
hrrr	NOAA HRRR	3 km	hourly	18 h hourly, 48 h on the 00/06/12/18Z cycles; the retained synoptic run fills the tail so ~48 h is always available	Default. The full soaring set, smoke and AQI.
rrfs	NOAA RRFS	3 km	00/06/12/18Z	84 h	NAM’s replacement. Same grid as HRRR.
nam	NOAA NAM CONUS nest	3 km	00/06/12/18Z	60 h	Retired by NCEP on 2026-10-14; nam then resolves to rrfs automatically.
gfs	NOAA GFS	0.25°	00/06/12/18Z	384 h (hourly to 120 h, 3-hourly after)
ecmwf	ECMWF IFS open data	0.25°	00/06/12/18Z	144 h (360 h on 00/12Z)	Synoptic fields only; no boundary-layer fluxes, so no soaring fields. CC BY 4.0.

Open-Meteo model slugs (ncep_hrrr_conus, gfs_seamless, ecmwf_ifs025, best_match, …) are accepted as aliases.

Each model’s current run, built hours and the retained extended run are published in /v1/meta.json and /v1/layers. A run becomes available hour by hour as NOAA publishes it, typically within 60–90 minutes of the cycle time for HRRR; forecasts always stitch the newest run with the previous synoptic run so the served horizon never shrinks.

Elevation

Point forecasts sample a 90 m DEM (Copernicus GLO-90) at your coordinates and lapse-correct 2 m temperature from the model’s own terrain height, which in mountains can differ from yours by hundreds of metres. Both heights are in the response (elevation, model_elevation). Pass elevation= to override the DEM, as Open-Meteo allows.

Retention

The API serves the current run and the previous synoptic run per model. History parameters (past_days, start_date) return 400 today; an archive of every analysis hour has been kept since September 2026 and a history product is planned.

Observations at a glance

Feed	Source	Cadence	Window
Radar	NOAA MRMS composite reflectivity	every 2 min, 5-min frames	trailing 2 h + nowcast to +60 min
Lightning	MRMS NLDN cloud-to-ground density	every minute	trailing 2 h
Stations	NOAA MADIS (mesonets, METAR, RAWS, CWOP, SNOTEL, HADS)	every 10 min	latest; 7 days of history per station
Soundings	NOAA radiosondes	every 10 min	7 days
Stream gauges	USGS NWIS	every 15 min	latest, plus on-demand history
Wildfire	NIFC WFIGS perimeters and incidents, NASA FIRMS VIIRS hotspots	hourly	hotspots 48 h
TFRs	FAA	every 15 min	active
Alerts	NWS	live	active
Forecast discussions	NWS AFDs, every office	every 5 min	current, 30 days of history