So far in January temperatures in Switzerland have been below zero for ten days and there is ice floating on Lake Constance. According to SRF Meteo, January hasn’t been this cold for 30 years.
So far the average temperature for January is below -3 degrees, 3 degrees lower than the long term average of 0.3 degrees. To find a colder January it is necessary to go back as far as 1987 when the average temperature was -4.3 degrees. 1987 brought Switzerland’s coldest reading ever: -41.8 degrees in La Brévine.
The 1987 record is unlikely to be broken however with temperatures predicted to rise between now and the end of the week.
The recent cold spell could be part of climate change. As higher global temperatures melt ice in the arctic, the temperature differential between cold arctic air and warmer southern air is declining. This impacts on the jet stream, an air current flowing in an easterly direction across Europe. Experts at SRF Meteo think this change might have weakened the jet stream, slowing the movement of the current cold weather system.
The two minute video below by the UK Met Office explains how the jet stream works.
This graphic published by National Geographic shows how much arctic ice has disappeared since 1980.