Switzerland's national day started in steamy fashion in many places including Altdorf in the canton of Uri, where night-time temperatures didn't drop below 27.5 degrees, beating the previous August 1st night-time record of 26.9 set in 1983, SRF Meteo said.
A rare summer foehn wind pushed temperatures up during the annual national holiday, with the hottest place in the country being Sevelen near St Gallen, which reached 35.7 degrees.
Other parts of eastern Switzerland reached similar heights, with 34.9 in Chur and 34.3 in Glarus.
In around 20 places in the country it was the hottest Swiss national day since records began, said SRF Meteo.
After the heat of the day, thunderstorms moved in bringing heavy rain, hail and high winds in some parts.
During the afternoon three cars were trapped by a mudslide on the high mountain road to Derborence in the canton of Valais. Fortunately no one was injured.
The road was shut for three hours while the debris was cleared away, Valais police told 20 Minutes.
A fire broke out at a house in Wienacht-Tobel in the canton of Appenzell Ausserrhoden after it was struck by lightning, 20 Minuten said.
During the night a violent thunderstorm moved across the country from the canton of Jura to Basel and on across Lake Constance.
In Eschenz in the canton of Thurgau 34mm of rain fell in just ten minutes, reported SRF Meteo.
Hurricane-strength winds battered many places, with winds as high as 170km/hr hitting Marthalen in the canton of Zurich and 134km/hr in Leibstadt in the canton of Aargau, said MeteoNews.
Wednesday's weather is set to be calmer, though temperatures will remain high, with the mercury surpassing 30 degrees across most of the country.