A month of June watered in the Jura arc, rather dry elsewhere
Following the sometimes stormy precipitation during the first week of June, the Jura arc, the entire canton of Neuchâtel and a northern North Vaud experienced excess rainfall. Delémont recorded the equivalent of 156 % of the reference period 1991-2020. But it was Chavornay (VD) station that measured the most important excess in Switzerland with 206 % of the reference. The station was struck by two violent thunderstorms on June 21 with 41.1 mm and June 30 with 63.1 mm. The Ajoie was an exception in the region with a rainfall deficit.
Elsewhere, precipitation and thunderstorms have been less numerous than usually and the rainfall was deficit. The Canton of Geneva posted a marked deficit with 55 % of the reference. This was also the case in the Pays-d’Enhaut and the Vaudois Pre-Alps. The Col des Mosses station, with 60.8 mm (41 % of the reference), even measured its driest June since the start of the measures in 1972. The whole canton of Friborg experienced in deficit rainfall, the deficit being the most marked towards the Pre -Alpine.
Valais has presented some regional differences. In general, precipitation has been in deficit. However, following storms located, certain Valais stations noted an excess rainfall as in Hérémence (136 % of the reference) or in Sion (116 % of the reference). The differences could be important for a few kilometers. If the Sierre station has experienced a deficit rainfall with 60 % of the reference, the Montana station has presented an excess rainfall with 107 % of the reference.
