Variables

The slug is the value to pass in the var query parameter.

Variable	Slug	Units
Mean Temperature	temp_mean	°C
Max Temperature	temp_max	°C
Min Temperature	temp_min	°C
Precipitation	precipitation	mm
Soil Temperature	soil_temperature	°C
Relative Humidity	humidity	%
Evapotranspiration	evapotranspiration	mm
Solar Radiation	solar_radiation	W/m²
Soil Moisture	soil_moisture	%
Mean Wind Speed	wind_speed	km/h
Max Wind Speed	max_wind_speed	km/h
Max Wind Gust	max_wind_gust	km/h

Not every variable is available on every endpoint — see the Current endpoint availability and Legacy endpoint availability matrices below.

Spatial resolution and downscaling

The API supports two spatial resolutions: a default ~25 km (0.25° grid) and a downscaled ~1 km (0.0083°) for select variables (Mean/Max/Min Temperature and Solar Radiation, marked in the matrix below). Access to 1 km downscaling is enabled at the account level — contact your ClimateAI account manager to enable it on an existing API key. Once enabled, the current endpoints expose a per-request use_downscaling flag to toggle it on or off per call.

Once enabled, downscaling applies only to the four downscalable variables; for all other variables the response is at the native 0.25° grid regardless. On the current endpoints, the per-request use_downscaling=true flag (default) requests the downscaled resolution; if the account isn't provisioned for 1 km, the flag has no effect and the response stays at 0.25°.

Current endpoint availability

Variable availability

Variable	Slug	Units	/forecast/stitched/*	/history/grid	Downscalable to 0.0083°
Mean Temperature	temp_mean	°C	✓	✓	✓
Max Temperature	temp_max	°C	✓	✓	✓
Min Temperature	temp_min	°C	✓	✓	✓
Precipitation	precipitation	mm	✓	✓
Soil Temperature	soil_temperature	°C	✓	✓
Relative Humidity	humidity	%	✓	✓
Evapotranspiration	evapotranspiration	mm	✓	✓
Solar Radiation	solar_radiation	W/m²	✓	✓	✓
Soil Moisture	soil_moisture	%	✓	✓
Mean Wind Speed	wind_speed	km/h	✓	✓
Max Wind Speed	max_wind_speed	km/h	✓	✓
Max Wind Gust	max_wind_gust	km/h	✓	✓

Granularity

Both /v2/forecast* and /v2/history accept daily (default), weekly (ISO weeks Mon–Sun, only complete weeks), or monthly (only complete months). Variable-aware aggregation: precipitation/evaporation are summed; temperature/humidity/wind are averaged.

Statistics

Endpoint	What's returned
/v2/forecast	Per-ensemble-member values
/v2/forecast/statistics	Mean and custom quantiles (any value in [0, 1]). No probabilistic terciles — see Migration.
/v2/history	Aggregated values (no quantiles, no terciles)

Legacy endpoint availability

Variable availability

Variable	Slug	Units	History	Climatology	Short-term	Subseasonal	Seasonal	Downscalable to 0.0083°
Mean Temperature	temp_mean	°C	✓	✓	✓	✓	✓	✓
Max Temperature	temp_max	°C	✓	✓	✓	✓	✓	✓
Min Temperature	temp_min	°C	✓	✓	✓	✓	✓	✓
Precipitation	precipitation	mm	✓	✓	✓	✓	✓
Soil Temperature	soil_temperature	°C	✓	✓	✓	✓	✓
Relative Humidity	humidity	%	✓	✓	✓	✓	✓
Evapotranspiration	evapotranspiration	mm	✓	✓	✓	✓	✓
Solar Radiation	solar_radiation	W/m²	✓	✓	✓	✓	✓	✓
Soil Moisture	soil_moisture	%	✓	✓	✓	✓	✖
Mean Wind Speed	wind_speed	km/h	✓	✓	✓	✓	✓
Max Wind Speed	max_wind_speed	km/h	✓	✓	✓	✖	✖
Max Wind Gust	max_wind_gust	km/h	✓	✓	first 10 days only	✖	✖

Granularity availability

Dataset	Daily	Weekly	Monthly	Notes
History	✓	—	—
Climatology	✓	✓	✓
Short-term Forecast	✓	—	—
Subseasonal Forecast	✓	✓	—	Weekly responses include probabilistic terciles in addition to quantiles.
Seasonal Forecast	✓	—	✓	Monthly responses include probabilistic terciles in addition to quantiles.

Statistics by dataset

History returns raw daily values, not statistical aggregates, and is excluded from this table. The remaining legacy datasets return:

Dataset	Mean	Quantiles [0.05, 0.25, 0.50, 0.75, 0.95]	Probabilistic terciles [0.00–0.33, 0.33–0.67, 0.67–1.0]
Climatology	—	✓	—
Short-term Forecast	✓	✓	—
Subseasonal Forecast (daily)	✓	✓	—
Subseasonal Forecast (weekly)	✓	✓	✓
Seasonal Forecast (daily)	✓	✓	—
Seasonal Forecast (monthly)	✓	✓	✓