Radiation API Parameters

Instantaneous Fluxes: Clear Sky Radiation | Diffuse Radiation | Direct Radiation | Global Radiation | Mean Global Radiation over the Last 10 Years| Longwave Radiation
Accumulated Energy: Accumulated Energy (Direct, Diffuse, Longwave, Global and Clear Sky Radiation)
Radiation on tilted surfaces:Radiation on tilted surfaces (Direct and Global)

Note: All radiation parameters are normalized on one square meter. The effective unit therefore is W/m² or J/m², respectively.

Clear Sky Radiation: Instantaneous Flux

Gives the instantaneous flux of clear sky radiation in Watts per square meter.

clear_sky_rad:W

Examples

Show the expected instantaneous flux of clear sky radiation for the next two days.

https://api.meteomatics.com/2025-11-04T00:00:00ZP2D:PT1H/clear_sky_rad:W/47.412164,9.340652/html

Diffuse Radiation: Instantaneous flux

Gives the instantaneous flux of diffuse radiation in Watts per square meter.

diffuse_rad:W

It is also possible to get the mean, maximum or minimum of the diffuse radiation for an indicated time interval.

diffuse_rad_<measure>_<interval>:W

Available measures: mean, min, max

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h

Examples

Show the five days forecast for diffuse radiation.

https://api.meteomatics.com/2025-11-04T00:00:00ZP5D:PT1H/diffuse_rad:W/50,10/html

Direct Radiation: Instantaneous Flux

Gives the instantaneous flux of direct radiation in Watts per square meter.

direct_rad:W

The mean, maximum or minimum of the direct radiation for an indicated time interval is given by:

direct_rad_<measure>_<interval>:W

Available measures: mean, min, max

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h

Examples

Show the five-day forecast for direct radiation.

https://api.meteomatics.com/2025-11-04T00:00:00ZP5D:PT1H/direct_rad:W/50,10/html

Global Radiation: Instantaneous Flux

Gives the instantaneous flux of global radiation (diffuse + direct radiation) in Watts per square meter.

global_rad:W

It is also possible to get the mean, maximum or minimum of the direct radiation for an indicated time interval.

global_rad_<measure>_<interval>:W

Available measures: mean, min, max

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h

Examples

Show the five-day forecast for global radiation.

https://api.meteomatics.com/2025-11-04T00:00:00ZP5D:PT1H/global_rad:W/50,10/html

Mean Global Radiation over the Last 10 Years

Gives the mean global radiation over the last 10 years on a certain date at a specific location.

global_rad_10y_mean:W

Examples:

Compare the mean global radiation of the last ten years with the global radiation of 2022.

Current situation:
https://api.meteomatics.com/2025-11-04T12:00:00ZP100D:P2D/global_rad_10y_mean:W,global_rad:W/50,10/html

The global radiation in winter compared to the 10 years mean:

validdate;global_rad_10y_mean:W;global_rad:W
2021-10-01T12:00:00Z;423.8;610.1
2021-11-01T12:00:00Z;280.5;103.4
2021-12-01T12:00:00Z;128.2;41.0
2022-01-01T12:00:00Z;102.3;158.2
2022-02-01T12:00:00Z;143.7;77.8

Current situation:
https://api.meteomatics.com/2025-11-04T12:00:00ZP4M:P1M/global_rad_10y_mean:W,global_rad:W/50,10/csv

Longwave Radiation: Instantaneous flux

Gives the instantaneous flux of longwave (thermal) radiation in Watts per square meter.

longwave_rad:W

It is also possible to get the mean, maximum or minimum of the longwave radiation for an indicated time interval.

longwave_rad_<measure>_<interval>:W

Available measures: mean, min, max

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h, 24h

Examples

Show the three days forecast for longwave radiation.

https://api.meteomatics.com/2025-11-04T00:00:00ZP3D:PT1H/longwave_rad:W/50,10/html

Show the min, mean and max longwave radiation accumulated over six hour intervals for the next three days.

https://api.meteomatics.com/2025-11-04T00:00:00Z--2025-11-07T00:00:00Z:PT1H/longwave_rad_min_6h:W,longwave_rad_mean_6h:W,longwave_rad_max_6h:W/50,10/html

Accumulated Energy

Gives the accumulated energy of direct, diffuse, longwave, global or clear sky radiation in Ws, Wh or J per square meter.

<type>_rad_<interval>:<unit>

Available type: global, direct, diffuse, longwave, clear_sky

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h, 24h

Available units: Ws, Wh, J

Examples

Show the longwave, direct, diffuse, global and clear sky radiation accumulated over one hour intervals for the next five days.

https://api.meteomatics.com/2025-11-04T00:00:00Z--2025-11-09T00:00:00Z:PT1H/longwave_rad_1h:J,direct_rad_1h:J,diffuse_rad_1h:J,global_rad_1h:J,clear_sky_rad_1h:J/52.652,7.865/html

validdate;longwave_rad_1h:J;direct_rad_1h:J;diffuse_rad_1h:J;global_rad_1h:J;clear_sky_rad_1h:J
2025-10-27T00:00:00Z;1216936.7;0.0;0.0;0.0;0.0
2025-10-27T01:00:00Z;1214343.5;0.0;0.0;0.0;0.0
2025-10-27T02:00:00Z;1221732.4;0.0;0.0;0.0;0.0
2025-10-27T03:00:00Z;1232331.4;0.0;0.0;0.0;0.0
2025-10-27T04:00:00Z;1241225.0;0.0;0.0;0.0;0.0
2025-10-27T05:00:00Z;1204490.4;0.0;0.0;0.0;0.0
2025-10-27T06:00:00Z;1227869.7;0.0;0.0;0.0;0.0
2025-10-27T07:00:00Z;1202397.4;0.0;12517.1;12517.1;52804.8
2025-10-27T08:00:00Z;1243182.8;0.0;90276.1;90276.1;387542.8
2025-10-27T09:00:00Z;1171076.9;124410.3;173341.1;297751.3;823487.0
2025-10-27T10:00:00Z;1142941.6;812872.9;194281.6;1007154.5;1173645.7
2025-10-27T11:00:00Z;1256031.6;289376.8;236942.2;526319.0;1380688.0
2025-10-27T12:00:00Z;1227443.1;210108.5;364937.7;575046.3;1415677.1
2025-10-27T13:00:00Z;1256175.2;24477.6;238197.9;262675.5;1276545.0
2025-10-27T14:00:00Z;1250853.1;37442.0;226703.5;264145.6;979830.8
2025-10-27T15:00:00Z;1220630.1;52822.4;140564.7;193387.1;568057.6
2025-10-27T16:00:00Z;1197334.4;6713.8;47920.8;54634.6;153635.7
2025-10-27T17:00:00Z;1030602.1;0.0;0.0;0.0;1158.7
2025-10-27T18:00:00Z;1162790.1;0.0;0.0;0.0;0.0
2025-10-27T19:00:00Z;1003997.3;0.0;0.0;0.0;0.0
2025-10-27T20:00:00Z;968842.9;0.0;0.0;0.0;0.0
2025-10-27T21:00:00Z;972063.8;0.0;0.0;0.0;0.0
2025-10-27T22:00:00Z;966194.1;0.0;0.0;0.0;0.0
2025-10-27T23:00:00Z;968960.9;0.0;0.0;0.0;0.0
2025-10-28T00:00:00Z;964116.6;0.0;0.0;0.0;0.0
2025-10-28T01:00:00Z;986263.3;0.0;0.0;0.0;0.0

Radiation on tilted surfaces

Gives the instantaneous flux, the minimum, maximum or mean flux over a time interval or the accumulated energy of direct or global radiation on a tilted surface with a certain orientation.

Instantaneous flux

<type>_rad_tilt_<tilt angle>_orientation_<orientation angle>:W

Min, max or mean flux for an indicated time interval

<type>_rad_tilt_<tilt angle>_orientation_<orientation angle>_<measure>_<interval>:W

Accumulated energy

<type>_rad_tilt_<tilt angle>_orientation_<orientation angle>_<interval>:<unit>

Available type: global, direct

Available intervals: 5min, 10min, 15min, 20min, 30min, 1h, 2h, 3h, 6h, 12h, 24h

Available units: Ws, Wh, J

The convention for the orientation: 180° means exposition to the south, 0° to the north, 90° to the east and 270° to the west

It's also possible to specify a tracking type:

<type>_rad_tracking_type_<tracking type>_tilt_<tilt angle>_orientation_<orientation angle>:W

<type>_rad_tracking_type_<tracking type>_tilt_<tilt angle>_orientation_<orientation angle>_<measure>_<interval>:W

<type>_rad_tracking_type_<tracking type>_tilt_<tilt angle>_orientation_<orientation angle>_<interval>:<unit>

Examples

Show the expected instantaneous flux of global radiation on a surface with 20° tilt and north-eastern orientation for the next seven days.

https://api.meteomatics.com/2025-11-04T00:00:00ZP7D:PT1H/global_rad_tilt_20_orientation_45:W/47.412164,9.340652/html
Show the expected accumulated direct radiation on a surface with 35° tilt and southern orientation for the next seven days.

https://api.meteomatics.com/2025-11-04T00:00:00ZP7D:PT24H/global_rad_tilt_35_orientation_180_24h:Ws/47.412164,9.340652/html