GFS & HRRR Forecast API

This API uses global NOAA GFS weather forecast and combines them with high-resolution HRRR forecasts. HRRR is a rapid-refresh model and updates every hour. High-resolution data are only available for the United States. For other locations, only GFS is used. For GFS, values are interpolated from 3-hourly to 1-hourly after 120 hours.

The API endpoint /v1/gfs accepts a geographical coordinate, a list of weather variables and responds with a JSON hourly weather forecast for 7 days. Time always starts at 0:00 today and contains 168 hours. If &forecast_days=16 is set, up to 16 days of forecast can be returned. All URL parameters are listed below:

Various weather variables and levels may be available for each NOAA NCEP model. Certain variables for the high-resolution GFS013 model are unavailable, so the standard GFS025 model is used instead. The local area models HRRR and NBM differentiate between rain and shower precipitation types. Probability data is directly available only for NBM, while Open-Meteo calculates precipitation probability for the GFS025 model.

The parameter &hourly= accepts the following values. Most weather variables are given as an instantaneous value for the indicated hour. Some variables like precipitation are calculated from the preceding hour as an average or sum.

The parameter &minutely_15= can be used to get 15-minutely data. This data is based on the HRRR model which is only available in North America. If 15-minutely data is requested for locations outside North America, data is interpolated from 1-hourly to 15-minutely.

15-minutely data can be requested for other weather variables that are available for hourly data, but will use interpolation.

Pressure level variables do not have fixed altitudes. Altitude varies with atmospheric pressure. 1000 hPa is roughly between 60 and 160 meters above sea level. Estimated altitudes are given below. Altitudes are in meters above sea level (not above ground). For precise altitudes, geopotential_height can be used.

All pressure levels have valid times of the indicated hour (instant).

Aggregations are a simple 24 hour aggregation from hourly values. The parameter &daily= accepts the following values:

On success a JSON object will be returned.

{
    "latitude": 52.52,
    "longitude": 13.419,
    "elevation": 44.812,
    "generationtime_ms": 2.2119,
    "utc_offset_seconds": 0,
    "timezone": "Europe/Berlin",
    "timezone_abbreviation": "CEST",
    "hourly": {
        "time": ["2022-07-01T00:00", "2022-07-01T01:00", "2022-07-01T02:00", ...],
        "temperature_2m": [13, 12.7, 12.7, 12.5, 12.5, 12.8, 13, 12.9, 13.3, ...]
    },
    "hourly_units": {
        "temperature_2m": "°C"
    }
}

In case an error occurs, for example a URL parameter is not correctly specified, a JSON error object is returned with a HTTP 400 status code.

{
    "error": true, 
    "reason": "Cannot initialize WeatherVariable from invalid String value
	    tempeture_2m for key hourly" 
}