Extracting STRÅNG data

You are free to use STRÅNG-data.

If you use STRÅNG data, please send us an email telling us. Continued availability of the data depends on continued funding, which depends on the usage of the data. If you use the STRÅNG data or some product based on the data in a publication or elsewhere please include an acknowledgement as follows:

STRÅNG data used here are from the Swedish Meteorological and Hydrological Institute (SMHI), and were produced with support from the Swedish Radiation Protection Authority and the Swedish Environmental Agency.

We would also appreciate to receive an electronic copy of any publication using STRÅNG data to the email address at the bottom of the page.

Here you can extract time series and field data with daily or hourly radiation data from the STRÅNG system data base.
Please select data type and time resolution.

Data type: Time resolution:
Fill out the form below by choosing a parameter (unit of the result in brackets) together with the dates defining the beginning and end of the time series and the latitude and longitude (decimal notation with negative west of Greenwich) for the location of your interest (default is Norrköping). Data is available from year 1999 and onward. Note that there are gaps in the data and that missing values show up as -999. Please check the output for error messages.

The result is an ASCII file with five columns separated by white space containing the year, month, day, hour and the selected radiation quantity interpolated from the field data using a bilinear method.

Note that the unit for PAR changed 2017-03-29. Before that date it was PPFD in micro moles per square meter and second and now it is irradiance in watts per square meter. Click here for more information about units and how to convert between them. The direct horizontal irradiance and the diffuse irradiance are only available from 2017-04-18 onwards.

Note that the values are instantaneous and refer to the full hour (UTC). Swedish local time is UTC + 1 h during winter time and UTC + 2 h during the summer. The dates when changing to (at 01.00 UTC, on the last Sunday in March) and from (at 01.00 UTC, on the last Sunday in October) summer time are stated by Swedish law due to EU-directive.

The RMSE (relative to the yearly mean value) when comparing hourly model data with point observations is approximately 30% for the global and the CIE UV irradiance while it is about 60% for the direct irradiance and the sunshine duration.

In the near future, access to STRÅNG data will only be available via the SMHI Open Data interface. An example of the recommended way to retrieve time series data (in plain ASCII) for the global irradiance during 00 - 23 UTC, 2020-06-21 at a point close to SMHI in Norrköping is given below:


Latitude:      Longitude:   

More information: mail to STRÅNG,
phone +46 (0)11 495 80 00