Thermal Comfort Indices - Mean Radiant Temperature, 1979-2020

Context The mean radiant temperature (MRT) is a human biometeorology parameter that is used to assess the linkages between the outdoor environment and human well‐being. Thermal comfort indices describe how the human body experiences atmospheric conditions, specifically air temperature, humidity, wind and radiation.

Definition The mean radiant temperature (°C) is a numerical representation of how human beings experience radiation. The mean radiant temperature (MRT) is based on the principle that the net exchange of radiant energy between objects is approximately proportional to their temperature difference multiplied by their ability to emit and absorb heat (emissivity). In this context the MRT applies to a person in an outdoor environment and is a function of the direct, diffuse and reflected thermal and solar radiation they experience.

Data Sources The mean radiant temperature (MRT) is computed using solar and thermal data from the ECMWF ERA5 reanalysis.

Supporting Information The data was collated on behalf of the Copernicus Climate Change Service (C3S). Further information about this index can be found in the C3S documentation resources in the Climate Data Store.

Visualisation and Navigation The mean radiant temperature (MRT) for each month and year from 1979 to 2020 is plotted on a map showing the European NUTS aggregation regions. The EUROSTAT NUTS classification (Nomenclature of Territorial Units for Statistics) is a hierarchical system for dividing up the economic territory of Europe. The size of the regions shown on the map can be adjusted by selecting the appropriate NUTS level: national level (NUTS-0), first sub-national level (NUTS-1), and second sub-national level (NUTS-2).

The regions on the map facilitate dynamic access to the underlying data. Hover the mouse pointer over a region to view its name or click on a region to request a time series plot. Likewise, the trans-national average for the EEA member and cooperating countries (EEA 38) can be accessed via the "Europe" bounding box.

The time series plot shows the area mean MRT for the chosen region.

Click and hover the mouse over the time series plot to view the data values and to reveal action buttons for features such as “zoom” and “download plot as a png”. Links below the plot enable the download of time series data in the spreadsheet compatible .csv format.