Long-Term Averages API subscription details

Global horizontal irradiation (GHI)

Ghm / Ghd

kWh/m²

Ghm: Average monthly and yearly sum of global horizontal irradiation.
Ghd: Average daily value for each month and the yearly average.

Direct normal irradiation (DNI)

Dnm / Dnd

kWh/m²

Dnm: Average monthly and yearly sum of direct normal irradiation.
Dnd: Average daily value for each month and the yearly average.

Diffuse horizontal irradiation (DIF)

Dhd

kWh/m²

Average daily value of diffuse horizontal irradiation, provided for each month and as a yearly average.

Global tilted irradiation (GTI)

Gim / Gid

kWh/m²

Gim: Average monthly and yearly sum of global irradiation on a tilted surface.
Gid: Average daily value for each month and the yearly average.

Ground surface albedo (ALB)

Alb

–

Average monthly and yearly ratio of solar irradiance reflected from the ground surface (albedo), calculated as the ratio of upwelling to downwelling fluxes.

Air temperature at 2 m (TEMP)

Td, Tmin, Tmax

°C

Td: Average; Tmin: minimum; Tmax: maximum monthly values of air temperature at 2 m above ground. Yearly values are provided for Td.

Wind speed at 10 m (WS)

Ws

m/s

Average monthly and yearly wind speed measured at 10 m above ground.

Relative humidity (RH)

Rh

%

Average monthly and yearly relative humidity at 2 m above ground.

Precipitation (PREC)

Prec

mm

Average monthly and yearly total precipitation (rainfall).

Precipitable water (PWAT)

Pwat

kg/m²

Average monthly and yearly column-integrated water vapor, representing total atmospheric moisture above ground.

PVOUT

Esm / Esd / Etm

kWh/kWp
kWh

Esm: Average monthly and yearly specific PV electricity output.
Esd: Average daily specific output per month.
Etm: Total PV production in kWh.