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The peak of the current heat wave is expected this weekend. Already on Saturday there were 35.5 degrees in Basel. This is the highest temperature this year north of the Alps. Similar temperatures are expected on Sunday, but it could get even hotter in the foehn areas.
The peak of the current heat wave is expected this weekend. Already on Saturday there were 35.5 degrees in Basel. This is the highest temperature so far this year north of the Alps. However, the 36.6 degrees on Friday in Biasca were not reached. Similar temperatures are expected on Sunday.
At the Friday absolute June high in the south
The value of 36.6 degrees in Biasca is an absolute high for the southern side of the Alps in June. So far, the south side record for the month of June comes from the hot summer of 2003. At that time, 36.5 degrees were measured in Grono, in the Grisons of Misox . However, it is difficult to classify the record temperature in Biasca, since data has only been available at this measuring point since September 2017. Biasca, located at the southern exit of the Leventina and the Blenio Valley, generally has very high temperatures. In Grono, on the other hand, “only” 33.9 degrees were measured on Friday, otherwise the temperatures in the south were mostly between 31 and 32 degrees.
Legend:
Locarno/TI
With north foehn it was 31.3 degrees in Locarno on Friday.
Irene Eichhorn
Similarly hot again on Sunday
Highs of between 32 and 36 degrees are expected again on Sunday. In the Alps there is also a southern foehn wind. It is therefore not impossible that the 37 degree mark will be reached in the afternoon. This would mean a new record for the month of June in our country. At the beginning of the coming week it will continue with temperatures of more than 30 degrees. However, it should just not be enough for absolute maximum values.
Legend:
Walenstadt
On Saturday it was cloudless in many places for a long time.
Peter Eicher
What was the highest June temperature so far?
In the official statistics of the state weather service, the 36.9 degrees on June 27, 1947 in Basel are still listed as a record. However, the measurement technology back then was completely different and cannot be compared with today’s instrumentation. With earlier measurement technology, maximum temperatures were automatically higher. During the last June heat wave in 2019, 36.9 degrees were also measured in Sion on June 28 and even 37.0 degrees on June 30. However, these values were subsequently corrected downwards, since the station at Sion Airport no longer corresponded to the international reference.
Legend:
Fiescheralp/Märjelensee.
The Alps have largely snowed out. No wonder, the zero degree limit is around 4300 meters.
Klaus Minning
The hottest time of the year is yet to come
Absolute maximum temperatures in June are rather rare. The hottest phase of the year is usually only reached during the dog days between July 23rd and August 23rd. If you analyze the annual highs in Switzerland in the 21st century more closely, you can see that the annual highs occurred nine times in July, eight times in August and only five times in June, and the absolute highs were also clear in July and August higher than in June. For August, the absolute maximum is 41.5 degrees (2003) and in July it was 39.7 degrees (2015). The current temperatures are rather modest.
Where is the heat coming from?
Since
days there is a low pressure area in front of the Portuguese Atlantic coast, where the classic Azores high should actually be at this time. The consequence of this is that southerly currents have repeatedly been able to set in from Spain to the Alps in recent weeks. This brought the first hot days in Switzerland about a month ago. Spain has been suffering from constant heat for days. In the Seville – Cordoba area, temperatures are almost constant around 40 degrees with maximum values of up to 43 degrees. Since the low-pressure area is now shifting towards Biscay, this heat is now moving towards the Alps. Since the sun is not quite as steep here as in Spain, the maximum temperatures are not quite as high. On Saturday, the center of the heat shifted from southern Spain to south-west France. 43 degrees were measured in Biarritz. But there were also 37 degrees near the Swiss border, for example in Colmar in Alsace.