Solar Solar Radiation Data

Accurate solar irradiance and weather data with global coverage: historical, real-time and forecast.

Solar radiation forecasting and historical data, worldwide

Based on our proprietary cloud and aerosol tracking and forecasting. Updated every 10-15 minutes, with forecasts extending 7 days ahead. Available at 5, 10, 15 or 30 minute time granularity - past, present and forecast.


Our customers use our solar radiation and weather data to:

  • Plan and monitor new solar projects

  • Estimate PV system yields with modelling tools such as PVsyst or PlantPredict

  • Create or improve in-house solar power forecasting

  • Conduct research (we offer free solar radiation data for non-commercial use)


Data Specifications


Core parameters:

  • Global Horizontal Irradiance (GHI)
  • Direct Normal Irradiance (DNI)
  • Diffuse Horizontal Irradiance (DIF, DHI)
  • Cloud Opacity
  • Temperature
  • Solar zenith angle
  • Solar azimuth angle

Historical and Recent data also includes:

  • Global Tilted Irradiance (GTI)
  • Wind Speed
  • Wind direction
  • Relative humidity
  • Surface pressure
  • Precipitable water

Forecast probabilities:

10th and 90th percentile forecasts provided for:

  • Global Horizontal Irradiance (GHI)
  • Direct Normal Irradiance (DNI)

Spatial coverage

All continents (Rapid update actuals and forecast data)

Global (forecasts)

Time granularity

Utility Scale Sites: 5, 10, 15, 20 or 30 minutes (period mean)

Other sites: 30 minutes (period mean)

Update frequency

Every 10 or 15 minutes

Time span (Forecast)

Present time to +7 days ahead

Time span (Realtime)

7 days ago to present time

Time span (Recent)

4 months ago to 2 days ago

Time span (Historical)

15 years ago to 2 days ago

Test now, for your site, free

Access solar radiation data via API (including CSV download) and begin your free trial in less than one minute!