Warnings for hot and cold weather
The purpose of the warnings on extreme temperatures is to prevent health problems resulting from cold and hot weather. The warnings are mainly intended for risk groups and people who work outdoors.
A heat wave warning is issued if stifling hot weather has been forecasted for some area in Finland. Criteria for cold weather warnings are based on wind chill index, which describes the combined effect of cold and wind. Warnings for hot and cold weather are for the next 5 days.
Warnings associated with extreme temperatures have three risk levels
hot: maximum daily temperature exceeds 27 degrees and mean temperature 20 degrees (yellow)
very hot: maximum daily temperature 30 degrees and mean temperature 24 degrees (orange)
extremely hot: maximum daily temperature 35 degrees and mean temperature 28 degrees (red).
A warning on cold weather, when the temperature or wind chill index is below:
-20 (yellow), -30 (orange) or -35 (red) degrees in Southern Finland
-25 (yellow), -35 (orange) or -40 (red) degrees in Central Finland
-30 (yellow), -40 (orange) or -45 (red) degrees in Northern Finland.