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Historical data. This can be past measurements from a weather station or model data for some point in the past.


The current calculation/measurement depending on type.



Forecasts are available in prerelease stability. This feature is still under active development and subject to non-backwards compatible changes. Make sure you follow updates on the changelog and give us feedback on the endpoints on

Forecast data. This is the output of one or multiple models for some point in the future.

Forecasts have several additional metadata attributes (available via the /metadata endpoint of the respective data source):

  • available_forecast_reftimes holds all available forecast reference times. The forecast reference time describes when the data was created, i.e. the forecast model was run.

  • last_forecast_reftime holds the newest available forecast reference time.

  • max_forecast_offset is the maximum allowed value for the forecast_offset parameter.

  • forecast_length describes how many time steps a single forecast has.


Due to their large size, only the last few forecasts are available. This means, specifying start and end outside of last_forecast_reftime will yield no results.


Currently, the available forecast duration (timerange covered by a forecast) is always forecast_length * freq for easier use. In the future, this may change, so this simple formula does not necessarily hold. For example a dataset might have 1H timesteps for the next 6 hours, 3H steps for the following 18 hours, and even lower resolutions after that. When available, this information will be displayed as part of the metadata of a dataset.

mode specific parameters


if mode is historical or forecast

The start date and time, supplied in YYYY-MM-DDThh:mm format (the time is optional).

In case of forecasts start is optional and defaults to the last forecast timestamp before now.


if mode is historical or forecast

The end date and time, supplied in YYYY-MM-DDThh:mm format (the time is optional).

In case of forecasts end is optional and defaults to the end of the forecast.


if mode is forecast

An optional offset allowing you to select an older forecast. forecast_offset counts backwards, so 0 is the most recent forecast, 1 the second most recent and so on. You can check the available_forecast_reftimes metadata attribute, and the offset will correspond to the index of the list.

The default value is 0, i.e. the most recently produced forecast is requested, and must be between 0 and max_forecast_offset.