Satellite Radiation API
Real-time Solar Irradiance From Multiple Satellites
Solar radiation data from NASA GOES satellites has not been integrated yet, so data is currently
unavailable for North America.
Data Sources
| Provider | Satellite | Region | Spatial Resolution | Temporal Resolution | Update frequency | Delay | Archive since |
|---|---|---|---|---|---|---|---|
| EUMETSAT LSA SAF | MSG | Europe, Africa, South America (only land) | 0.05° (~ 5km) | 15 minutely | Every Hour | 2 Hours | 2025 |
| IODC | Europe, Africa, India (only land) | 0.05° (~ 5km) | 15 minutely | Every Hour | 2 Hours | 2025 | |
| EUMETSAT CM SAF SARAH3 | MSG | Europe, Africa, South America | 0.05° (~ 5km) | 30 minutely | Every Hour | 2 Days | 1983 |
| JMA JAXA | Himawari-9 | India, Asia, Australia, New Zealand | 0.05° (~ 5km) | 10 minutely | Every 10 minutes | 20 Minutes | 2022 |
| NASA (not yet available) | GOES-East | North & South America | 0.05° (~ 5km) | N/A | N/A | N/A | N/A |
| GOES-West | Pacific Ocean & Alaska | N/A | N/A | N/A | N/A | N/A |
API Documentation
The Satellite Radiation API integrate solar radiation data from various satellite datasets into a single consistent endpoint. Different geostationary satellites are used to provide global coverage.
- Himawari direct and diffuse radiation JMA JAXA provides only shortwave radiation data and does not offer direct or diffuse solar radiation. Open-Meteo applies the separation model from Razo, Müller Witwer to calculate direct radiation from shortwave solar radiation.
- Instantaneous Values Correction: All satellites provide data as instantaneous values. However, a full Earth scan takes approximately 10–15 minutes. As a result, the top and bottom of each scan have a significant time difference. To ensure comparability with data sources like weather models, OpenMeteo corrects for these scan time differences and derives backward-averaged values.
- Different temporal resolutions: Data is available in 10, 15 or 30–minutely steps. For compatibility, the API returns 1–hourly data. If you want to access the underlying time resolution, make sure to set "Temporal resolution for hourly data" to "native".
Hourly Parameter Definition
The parameter &hourly= accepts the following values. All data is provided in W/m². Solar radiation parameters are available as either instantaneous values or backward averages over the past hour. If you select 10/15/30-minute data, the backward averages will use the same 10/15/30-minute intervals.
| Variable | Valid time | Description |
|---|---|---|
| shortwave_radiation | Preceding hour mean | Shortwave solar radiation as average of the preceding hour. This is equal to the total global horizontal irradiation. This is equal the sum of direct and diffuse radiation. |
| diffuse_radiation | Preceding hour mean | Diffuse solar radiation as average of the preceding hour |
| direct_radiation | Preceding hour mean | Direct solar radiation as average of the preceding hour on the horizontal plane. |
| direct_normal_irradiance | Preceding hour mean | Direct solar radiation as average of the preceding hour on the normal plane (perpendicular to the sun). Often denoted DNI. |
| global_tilted_irradiance | Preceding hour mean | Total radiation received on a tilted pane as average of the preceding hour. The calculation is assuming a fixed albedo of 20% and in isotropic sky. Please specify tilt and azimuth parameter. Tilt ranges from 0° to 90° and is typically around 45°. Azimuth should be close to 0° (0° south, -90° east, 90° west). If azimuth is set to "nan", the calculation assumes a horizontal tracker. If tilt is set to "nan", it is assumed that the panel has a vertical tracker. If both are set to "nan", a bi-axial tracker is assumed. |
| terrestrial_radiation | Preceding hour mean | The solar radiation at the top of the atmosphere, unaffected by clouds or aerosols. It is purely calculated using the solar position factor multiplied by the solar constant of 1367.7 W/m². This differs from clear sky radiation, which accounts for aerosols but not clouds. |
| *_instant | Instant | All solar radiation parameters can be converted to instantaneous values by integrating the solar zenith angle. Instantaneous values are useful for comparing data with local measurements. However, for energy calculations or comparisons with numerical weather models, backward-averaged data is recommended. |