Historical Time Series

Historical and TMY

Global irradiance and weather data records designed and built for solar and cleantech

The world's most accurate historical irradiance and weather data. 20+ weather parameters tailored to solar energy applications, from 2007 to 7 days ago. Available in JSON via synchronous API, or instant CSV web download.

Time Series Data

Tracking the world's clouds in the finest detail

Designed for Solar, from the ground up. Never rely on generic weather model data again. Solcast's real time and forecast data tracks and forecasts real clouds at a resolution of 1-2km and 5 minutes. Our irradiance data and PV power data is updated every 5 to 15 minutes, downscaled to 90 metre resolution. Aerosol and albedo effects are explicitly treated.

Time Series Data


Full suite of high resolution weather data

Other weather data from leading reanalysis datasets completes the full suite of 20+ parameters available at 5, 10, 15, 30 and 60 minute resolutions. Coverage from 2007 to 7 days ago.


We provide upfront and clear accuracy and validation information

Be confident that our data is fit for purpose.

Explore up to date, independent validation statistics at locations similar to your area of interest.

Data Accuracy
Data Availability

Data Access

Get data via synchronous API or instant CSV download

Synchronous API returns JSON data in 1-5 seconds per request, and requests can be submitted in parrallel up to your account rate limit.

Web downloads for up to 20 locations at at time. Choose from multiple file types including CSV, ready to use in your favourite simulation software.

Historical Time Series Data Specifications

Geographic coverage

Global (note: far ocean and polar regions are coarser resolution)

Temporal coverage

January 2007 to 7 days ago (for past 7 days to present time and forecasts, use our Live and Forecast data)

Temporal resolution

5, 10, 15, 30 & 60 minutes (period-mean values)

Spatial resolution

90 meters (irradiance, PV power, snow soiling, cloud parameters, and other parameters across all regions)

Data parameters

The following data parameters are available.

  • Global Horizontal Irradiance (GHI) (W/m2)^
  • Direct Normal Irradiance (DNI) (W/m2)^
  • Diffuse Horizontal Irradiance (DHI) (W/m2)^
  • Global Tilted Irradiance (GTI) (W/m2)^
  • Advanced PV Power Output (MW)^
  • Rooftop PV Power Output (kW)^
  • Cloud Opacity (%)
  • Air Temperature (°C)
  • Solar Zenith Angle (°)
  • Solar Azimuth Angle (°)
  • Albedo (%)
  • Wind Speed (10m) (m/s)
  • Wind Speed (100m) (m/s)
  • Wind Direction (10m) (°)
  • Wind Direction (100m) (°)
  • Relative Humidity (%)
  • Precipitation Rate (mm/h)
  • Surface Pressure (hPa)
  • Precipitable Water (kg/m2)
  • Dewpoint Temperature (°C)
  • Snow Depth Water Equivalent (cm)
  • Snow Depth (cm)
  • Snow Soiling Loss - Rooftop (%)
  • Snow Soiling Loss - Ground Mounted (%)

^ Clear-sky scenarios also available for these parameters

Data access

API or Web download

Download wait time

API: synchronous requests. Web download: seconds.

File formats


Data formats

Solcast standard, PVsyst (60 minute only)

Time zone

UTC, longitudinal, or user-specified fixed offset.