Variables

Surface variables — availability matrix

✅ Available · — Not available

Variable	Units	GFS	ECMWF-IFS	HRRR	NAM	ICON-EU	ICON-Global	AROME
air_temperature_2m	K	✅	✅	✅	✅	✅	✅	✅
dewpoint_temperature_2m	K	✅	✅	✅	✅	✅	✅	✅
relative_humidity_2m	%	✅	✅	✅	✅	✅	✅	✅
wind_u_10m	m s-1	✅	✅	✅	✅	✅	✅	✅
wind_v_10m	m s-1	✅	✅	✅	✅	✅	✅	✅
wind_gust_10m	m s-1	✅	✅	✅	✅	✅	✅	✅
mean_sea_level_pressure	Pa	✅	✅	✅	✅	✅	✅	✅
total_precipitation	kg m-2	✅	✅	✅	✅	✅	✅	✅
total_cloud_cover	%	✅	✅	✅	✅	✅	✅	✅
low_cloud_cover	%	✅	✅	✅	✅	✅	✅	✅
mid_cloud_cover	%	✅	✅	✅	✅	✅	✅	✅
high_cloud_cover	%	✅	✅	✅	✅	✅	✅	✅
cape	J kg-1	✅	✅	✅	✅	✅	✅	—
visibility	m	✅	✅	✅	✅	✅	✅	✅
snow_depth	m	✅	✅	✅	✅	✅	✅	✅
wind_u_50m	m s-1	✅	—	—	✅	—	—	—
wind_v_50m	m s-1	✅	—	—	✅	—	—	—
wind_u_80m	m s-1	✅	✅	✅	✅	✅	✅	—
wind_v_80m	m s-1	✅	✅	✅	✅	✅	✅	—
wind_u_100m	m s-1	✅	✅	—	✅	—	—	—
wind_v_100m	m s-1	✅	✅	—	✅	—	—	—

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Energy applications

For wind energy, the API provides U and V wind components at 50 m, 80 m, and 100 m. The 80 m level corresponds to a common turbine hub height.

Wind speed from components:

wind_speed = sqrt(wind_u² + wind_v²)

Wind direction from components (meteorological convention, degrees from north):

wind_direction = (270 - atan2(wind_v, wind_u) * 180/pi) % 360

Hub-height wind availability by model:

Height	GFS	ECMWF-IFS	HRRR	NAM	ICON-EU	ICON-Global	AROME
50 m	✅	—	—	✅	—	—	—
80 m	✅	✅	✅	✅	✅	✅	—
100 m	✅	✅	—	✅	—	—	—

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Pressure-level variables

Pressure-level variables follow the naming pattern:

{quantity}_{level}hpa

Available levels: 1000, 850, 700, 500, 300, 250 hPa.

Available quantities:

Pattern	Units	Description
temperature_{level}hpa	K	Air temperature
u_wind_{level}hpa	m s-1	U-component of wind
v_wind_{level}hpa	m s-1	V-component of wind
specific_humidity_{level}hpa	kg kg-1	Specific humidity
geopotential_height_{level}hpa	m	Geopotential height
vertical_velocity_{level}hpa	Pa s-1	Vertical velocity (omega)

Examples: temperature_500hpa, u_wind_850hpa, geopotential_height_300hpa.

Pressure-level variables are available from the /profile endpoint. See Forecast Endpoints — /profile.

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Unit conversion

Values are returned in CF-standard units. Common conversions:

From	To	Formula
K (temperature)	°C	°C = K − 273.15
Pa (pressure)	hPa	hPa = Pa / 100
kg m-2 (precipitation)	mm	mm = kg m-2 (water density 1 kg/L)
m s-1 (wind)	km/h	km/h = m s-1 × 3.6
m s-1 (wind)	knots	kn = m s-1 × 1.944