Switzerland is on track to record one of the hottest and driest Mays in its history.
The federal weather service says national temperatures have run 1.8 degrees above average – the fourth-warmest May since measurements began in 1864. Rainfall is down to just 56% of normal, with parts of Graubünden and the Engadine receiving less than half their usual totals.
The Confederation has issued a level-two drought alert for the Alps and the eastern Plateau, with no rain in the immediate forecast.
Valais hit 33.9 degrees on Tuesday, and the early heat is setting up a difficult summer for water supplies and forest-fire risk.