Forecast Data API

Get irradiance, weather and power forecasts from the present time up to 14 days ahead for the requested location, derived from satellite (clouds and irradiance over non-polar continental areas, nowcasted for approx. four hours ahead) and numerical weather models (other data and longer horizons).

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The module ForecastClient has the following available methods:

Endpoint	Purpose	API Docs
GetForecastRadiationAndWeather	Get irradiance and weather forecasts for the requested location from the present up to 14 days ahead, derived from satellite (clouds and irradiance over non-polar continental areas, now casted for approx. four hours ahead) and numerical weather models (other data and longer horizons).	details
GetForecastRooftopPvPower	Get basic rooftop PV power forecasts from the present time up to 14 days ahead for the requested location, derived from satellite (clouds and irradiance over non-polar continental areas, nowcasted for approx. four hours ahead) and numerical weather models (other data and longer horizons). The basic rooftop power simulation is only suitable for residential and smaller C&I rooftop sites, not for grid-scale sites. Attention hobbyist users If you have a hobbyist user account please use the Rooftop Sites (Hobbyist) endpoints.	details
GetForecastAdvancedPvPower	Get high-spec PV power forecasts for the requested site from the present up to 14 days ahead, derived from satellite (clouds and irradiance over non-polar continental areas, nowcasted for approx. four hours ahead) and numerical weather models (other data and longer horizons).	details

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GetForecastRadiationAndWeather

Parameters: latitude, longitude, hours, period, tilt, azimuth, arrayType, outputParameters, terrainShading, format

Example Usage:

using Solcast.Clients;

var forecastClient = new ForecastClient();
var response = await forecastClient.GetForecastRadiationAndWeather(
    latitude: -33.856784,
    longitude: 151.215297,
    period: "PT30M",
    tilt: 30.0f,
    azimuth: 180.0f,
    format: "csv"
);
Console.WriteLine(response.RawResponse);

Sample Output:

air_temp	dni	ghi	period_end	period
13	0	0	2025-07-14T08:30:00Z	PT30M
13	0	0	2025-07-14T09:00:00Z	PT30M
...	...	...	...	...
13	0	0	2025-07-16T07:30:00Z	PT30M
12	0	0	2025-07-16T08:00:00Z	PT30M

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GetForecastRooftopPvPower

Parameters: latitude, longitude, capacity, hours, period, tilt, azimuth, installDate, lossFactor, outputParameters, terrainShading, format

Example Usage:

using Solcast.Clients;

var forecastClient = new ForecastClient();
var response = await forecastClient.GetForecastRooftopPvPower(
    latitude: -33.856784,
    longitude: 151.215297,
    capacity: 5.0f,
    format: "csv"
);
Console.WriteLine(response.RawResponse);

Sample Output:

pv_power_rooftop	period_end	period
0	2025-07-14T08:30:00Z	PT30M
0	2025-07-14T09:00:00Z	PT30M
...	...	...
0	2025-07-16T07:30:00Z	PT30M
0	2025-07-16T08:00:00Z	PT30M

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GetForecastAdvancedPvPower

Parameters: resourceId, hours, outputParameters, period, applyAvailability, applyConstraint, applyDustSoiling, applySnowSoiling, applyTrackerInactive, terrainShading, format

Example Usage:

using Solcast.Clients;

var forecastClient = new ForecastClient();
var response = await forecastClient.GetForecastAdvancedPvPower(
    resourceId: "ba75-e17a-7374-95ed",
    format: "csv"
);
Console.WriteLine(response.RawResponse);

Sample Output:

pv_power_advanced	period_end	period
0	2025-07-14T08:30:00Z	PT30M
0	2025-07-14T09:00:00Z	PT30M
...	...	...
0	2025-07-21T07:30:00Z	PT30M
0	2025-07-21T08:00:00Z	PT30M

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