The national average temperature in May was 0.4 °C above the 1991-2020 norm. In the Upper Engadine, there were values of almost 1 °C above the norm. In the low-lying areas of the southern side of the Alps and in the Valais, the May temperature was in the range of the 1991-2020 norm.
From 1900 to the beginning of the 1980s, the May temperature showed no clear long-term trend towards higher or lower values, apart from periodic fluctuations. From the second half of the 1980s, there was a strong warming within a few years. During this time, the May temperature shifted to a level around 2 °C higher.
Line graph showing May temperature
Fig. 1: The May temperature in Switzerland since measurements began in 1864. The red dot shows the current May (9.3 °C). The green dashed line shows the 1991−2020 norm (8.9 °C), the red line the 20-year moving average.
Persistently wet
From the beginning of May, a long period of precipitation set in in Switzerland. Only the 3rd and 4th of May were sunny across the country. On the northern side of the Alps, the period of precipitation mostly lasted until the 16th, and in tunisia phone number library eastern Switzerland until the 17th of May. On the southern side of the Alps, the wet period lasted, with short interruptions, until the 20th of May.
Unusually heavy rainfall was recorded locally. On May 5, 113 mm fell on the Napf within a day. This was the second highest daily total since measurements began in 1978. On May 16, Schwägalp at the foot of the Säntis recorded 119 mm, the fourth highest daily total since measurements began in 1972. In the south, the highest daily totals remained rather modest, with maximum values of around 50 mm on May 9.
Persistently cloudy
From May 8th to May 20th, there was persistently little amazon marketing in japan sunshine throughout Switzerland. On the southern side of the Alps, the cloudy weather continued until May 21st. However, there was a little more sunshine in the south from May 13th to May 15th.
Long cool period
From May 4 to 9, mild and increasingly humid air flowed awb directory into Switzerland from the west and southwest. The average daily temperature across the country was several degrees above the 1991-2020 norm.
On May 10 and 11, Switzerland was hit by cool air from the northwest. With the subsequent setting in of the bise, the average daily temperature remained below the 1991-2020 norm until May 20. The coolest days on the northern side of the Alps, in the Valais and in the Engadine were from May 16 to 18. In mountainous areas, the average daily temperature fell regionally by up to 7 °C below the norm and it snowed down to around 1400 m.