Warnings for hot and cold weather

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.

cold winter day in Helsinki

Photo: Eija Vallinheimo

Warnings associated with extreme temperatures have three risk levels

  • Heat wave warning:

    • warm: maximum daily temperature exceeds 27 degrees and minimum temperature 14 degrees  (yellow)
    • very warm: maximum daily temperature 30 degrees and minimum temperature 18 degrees (orange)
    • extremely warm: maximum daily temperature 35 degrees and minimum temperature 20 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.

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.