Monthly Averages

Monthly and annual solar averages provided in a single file

Historical and TMY

Designed to provide high volumes of solar resource data quickly and effectively at a competitive price. Prospect for solar sites establish feasibility, or get a second opinion.

Trusted in 24x7 operations by 30,000+ users worldwide, including these brands

Cloud and Irradiance tracking

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 and PV power data is updated every 5 to 15 minutes. Aerosol and albedo effects are explicitly treated.


Integrate with your PV design workflow

Multiple file formats supports included CSV and JSON. Includes up to five API calls a month and several unmetered locations for developing your integration. Direct downloads through the API Toolkit available.

Data Access

Quickly access key irradiance and weather data via API

Provides GHI, DNI, DHI, GTI, Temperature, and wind speed. Global tilted irradiance for fixed and single access tracking systems supported.


Dataset supported by independent global validation

Monthly and annual average data has low uncertainty and a quantified error range, making the data suitable for resource assessment, yield analysis, financial modelling, and any application requiring climatological irradiance data.

Monthly plans
5 requests per month free.
Paid plans from $49/month.
Starter Plan
Includes 20 requests /month
Pro Plan
Includes 1000 requests /month
Max Plan
Includes 5000 requests /month

Each request includes 12 monthly average and annual value at 1 location

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Price Calculator (USD)

Starter Plan $49

Monthly Averages Data Specifications

Geographic voverage

Global, except for ocean and polar regions.

Temporal coverage

2007 to 2018

Temporal resolution

Average daily value per month, average monthly value, and average annual value

Spatial resolution

2km (irradiance and cloud parameters, over all non-polar continental areas and nearby islands)
27km (other parameters, and polar or remote oceanic regions)

Pxx (Probability of exceedance) options


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)
  • Temperature (°C)
  • Wind Speed (10m) (m/s)
Data access

Via the Solcast Web Toolkit & Solcast API

Download wait time

Web Toolkit: typically 5 minutes
API: less than 100ms

File formats


Data formats

Solcast standard, PVsyst, SAM, TMY3

Time zone

UTC (default for Solcast), longitudinal (default for SAM, PVsyst, TMY), or user-set