The purpose of the warnings on extreme temperatures is to prevent health problems resulting from cold and warm weather. The warnings are mainly intended for risk groups and people who work outdoors.
Heat wave warning is issued if stifling hot weather, lasting at least for three days, 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 next 5 days.
The warnings in force can be checked on the warnings page. On the map, warnings on hot weather are indicated by a red thermometer and warnings on cold weather by a blue thermometer.