Cold Spell Duration

Why is the content of this map important?

Cold spells are unusually long-lasting cold periods when temperature drops much below normal conditions. They have strong negative impacts on many aspects of society including health, infrastructure and agriculture; thus it is beneficial to understand how cold spells may alter under future climate change.

Which sectors are affected by this result?

Heart/respiratory diseases and strokes increase during cold spells. Consumer demand for electrical power rises, which can lead to overloads that can result in power cuts. Transport infrastructure may partly collapse in case of extremely strong and long cold spells. Fruit trees can die in unusual cold conditions.

What is shown on the maps?

The 1971-2000 period shows that cold spell duration varies from 3 to 9 days across Europe, with a maximum of up to 10 days over Central and eastern Europe. When the global mean temperature increases by 2°C, the duration of cold spells is strongly reduced. At this warming level, cold spells which are typical for 1971-2000 almost completely disappear in Scandinavia and Iberian Peninsula, and in Central and eastern Europe cold spell duration is halved from 6-8 days to 2-4.

Details and further information:

Cold spell duration is defined accordingly to recommendations from the Expert Team on Climate Change Detection and Indices (ETCCDI). They are estimated as a number of days when daily minimum temperature is below its climatological 10th percentile for at least 6 consecutive days. In the 2°C future warming period the 10th percentile for 1971-2000 is used as a reference. Cold spell duration is calculated annually for each year and when averaged over 30-year periods can be less than 6 days. This simply means that cold spells occur only in some years but not every year.

Additional information: