As far as temperatures are concerned, June 2024 is quite precisely within the multi-year average. What is more striking are the regionally intense rainfall and sunshine below the national average.
Quite normal from a temperature point of view
If the month of June has so far seen several summer days with temperatures above 25 degrees, one or two heatwave days with temperatures above 30 degrees have only been recorded in the eastern half of the country.
Fig. 1: Previous number of heatwave days in June 2024; Source: MeteoNews, Ubimet
In the meantime, a kind of sheep cold has been felt, with the coolest day in the north being June 11. Overall, the temperature balance is balanced across the country, with a minimal surplus. This surplus may still increase slightly over the last two days, as Saturday will be warm over a large part of the territory.
Fig. 2: Temperature deviation to date in June 2024 from the long-term average; Source: MeteoNews, Ubimet
Inhomogeneous distribution of precipitation
During this month, it rained several times, and sometimes intensely. Already on the first weekend, northeastern Switzerland received large amounts of rain, Lake Constance and many rivers were in flood. On June 21, heavy stormy rains in the Misox caused deaths and enormous damage to infrastructure. On June 25, it was especially the western regions of the country that were strongly affected. HAS L’Auberson, 90.9 mm of rain fell in one hour! The highest hourly rain total recorded so far in Switzerland is only slightly higher, with 91.2 mm in Lugano (August 28, 1997). The high intensities of precipitation are explained not only by the instability of atmospheric stratification, but also by an often high value of precipitable water in recent times.
Fig. 3: Historical deviation of precipitation in June 2024 from the multi-year average; Source: MeteoNews, Ubimet
Across the country, June 2024 has so far been only 10% too wet. The distribution is, however, very heterogeneous, because some regions were clearly too humid. What’s more problematic is that a lot of them fell in a short time. The level of Lake Constance remains high, the soils are saturated and many mountain slopes are now waterlogged. THE heavy precipitation which are announced again for tomorrow Saturday and part of the day Sunday raise fears of new regional problems!
Less sun than usual
The contrast between June 2023 and today’s June couldn’t be greater! Last year we had lots of sunshine and blue skies, but this year the sun is having a much harder time breaking through. Even for the sunniest resorts in comparison, there is a deficit. Across the country, around 1/4 of the hours of sunshine are missing!
Fig. 4: Historical deviation of sunshine duration in June 2024 compared to the multi-year average; Source: MeteoNews, Ubimet
The final figures will be published here in early July.
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