Solcast offers two variants of TMY: TMY P50 and TMY PXX (inclusive of P50, P75, P90, & P95).

Both of TMY P50 and TMY PXX can be accessed through our API Toolkit, and our TMY P50 files are available through a fast, low cost API service.

The TMY P50 API includes access to 2x free TMY files per month in our ‘Free Tier’ subscriptions, with paid options starting at $49 USD / month with no lock-in contract. See details on the Solcast pricing page.

If you are interested in TMY P50 API access, you can review our API docs here, to see if the service is a fit for your business.

You can access this API based service directly, after you sign-up for your free account in the Solcast API Toolkit.

About TMY Files

A TMY, or Typical Meteorological Year, is a collation of historical weather data for a specified location for a one year period.

The dataset is derived from a multi-year Time Series specifically selected so that it presents the unique weather phenomena for the location, and provides annual averages that are consistent with long term averages.

All TMY files contain exactly 8760 rows of data, each corresponding to an hourly period in an ‘average’, or ‘typical’ year. TMY data is frequently used by solar engineers, as a data input to energy system simulations.

TMY data specifications

Pxx (Probability of exceedance)	Basic TMY	Extended TMY	Available on request
	P50	P50, P75, P90, P95	Pxx
Coverage	Global, except for ocean and polar regions
Spatial resolution of satellite data	1-2 km
Time granularity	60 minute
Timespan of database used to generate TMY	January 2007 to 7 days ago
Parameters	Global Horizontal Irradiance (GHI, W/m2) Direct Normal Irradiance (DNI, W/m2) Direct (Beam) Horizontal Irradiance (EBH, W/m2) Diffuse Horizontal Irradiance (DIF, DHI, W/m2) Global Tilted Irradiance (GTI, W/m2) Cloud Opacity (%) Albedo (%) Solar Zenith angle (°) Solar Azimuth angle (°) Temperature (TEMP, °C) Wind Speed (WS, m/s) Wind Direction (WD, °) Relative Humidity (RH, %) Surface Pressure (AP, hPa) Precipitable Water (PWAT, kg/m2) Snow Depth (SWDE, cm) Dew Point (DWPT, °C)
Files provided	Solcast standard CSV PVsyst SAM TMY3
Time zone	UTC (default for Solcast) Longitudinal (default for SAM, PVsyst, TMY)
Database update frequency	Daily (recent months are considered in TMY scenario)
Access method	Data can be ordered and downloaded via the Solcast API Toolkit TMY P50 files can also be directly retrieved via API
Download wait time	API Toolkit Request form: Typically 1 to 9 minutes Synchronous TMY P50 API: less than 100ms