After the snowfalls of the past few days, polar air is pushing temperatures in Switzerland far below zero. It has never been so cold this year. But on Wednesday the thaw should start.
Snow covers trees, photographed in Hüttikon.
After an extraordinarily mild autumn, winter has finally taken hold of Switzerland – as it should be, with a largely covered blanket of snow and bitterly cold temperatures. In the lowlands, the snow depth is between 5 and 10 centimeters, in the foothills of the Alps between 20 and 30 centimeters. At high altitudes, however, there is still much less snow than usual at this time of year. According to the latest Avalanche bulletin of the Institute for Snow and Avalanche Research (SLF) from Monday morning there is currently only an average amount of snow in the westernmost part of Lower Valais. At 2500 meters, the snow depth in western Lower Valais and in north-western Ticino is around 80 centimeters. In the other Alpine regions there is only 40 to 60 centimeters of snow, in central Valais and in central Grisons even less.
The white splendor should remain in Switzerland until Wednesday. This is due to the freezing cold that has been keeping Switzerland under control since Sunday and will continue until Tuesday. On Monday night, Switzerland even had the coldest night of the year. According to one, the lowest temperature was Overview of Meteonews measured at -27 degrees on the Ofen Pass (1970 meters above sea level). In Samedan (1705) in the Upper Engadine, the temperature fell to -26.2 degrees. In La Brévine (1050) in the Neuchâtel Jura it was -25.3 degrees cold. Although it was also frosty on the central plateau, it was much milder than at higher altitudes. In Zurich Fluntern, -7.2 degrees were measured on Monday night. At Zurich Airport, the thermometer fell to -9 degrees on Sunday evening.
Children sledging through a freshly snow-covered landscape, recorded in St. Margrethenberg.
Far from any records
Even though the coldest night of the year was measured, the temperatures remained well below the previous record values. For example, it had already been -36.2 degrees on the Ofen Pass, as it was in a Overview of Meteonews called. In La Brévine, the “Siberia of Switzerland”, the thermometer had even fallen to -42.5 degrees in 1962. On December 20, 1981, minus 18 degrees was recorded at Zurich Airport.
Warm front melts the snow
The polar air will also bring icy temperatures on Monday. On Tuesday, a low over the Bay of Biscay will direct a warm front to Switzerland, according to the SRF Meteo forecast. However, temperatures are likely to remain close to freezing in many areas. Thaw and precipitation are only announced for Wednesday and Thursday. Then it should only come to freezing rain and freezing rain. Later, the white splendor in the lower altitudes is likely to melt away again.
Is there a white Christmas?
And the most important question: is there a white Christmas? The forecasters are not exactly helpful with the answer: “It is still too early to answer this question”, it says at Meteo News. A reasonably reliable trend for a white Christmas is only possible after December 15th.
The weather service Meteonews has examined at selected locations how common white Christmases have been since 2001. Since then, St. Gallen has mostly had snow on Christmas days (a total of twelve times or 57 percent). In Bern and Zurich it was the same for a total of six years (29 percent). In Geneva it was only white for two years (10 percent).
It is striking that there were significantly more white Christmases in the first decade (2001-2011) than in the second decade up to 2021. Since 2011, white Christmases have only occurred sporadically.
Danger of avalanches increased a little
The avalanche danger has now increased somewhat. Especially on shady slopes above around 2200 to 2400 meters there are still weakly fixed layers under the snow cover. This is partially covered by so much snow that large avalanches are also possible.
The avalanche danger for Monday is still low in the northernmost foothills of the Alps. Otherwise, however, it has increased to moderate across the board. It is significant (level 3 out of 5) in western Valais, the Bernese Oberland, the Central Alps and the Engadin.