As summer reaches the halfway point, the average temperature so far is four degrees warmer than the norm, SRF Meteo has said.
In recent weeks Switzerland has experienced very hot and sunny weather, interspersed with dramatic storms bringing torrential rain.
Temperatures have been significantly hotter than usual.
Normally the southern canton of Valais has by this point had 26 days where the mercury has reached 25 degrees or above. However this summer it has already had 35 days, said SRF Meteo.
The weather station at Sion, in the Valais, has recorded 17 days above 30 degrees – classed as a heatwave – ten more than the average of seven heatwave days.
Generally across Switzerland the sun shone for more days in June and early July than usual, it added.
READ ALSO: Swiss snowman predicts hot summer ahead
June was the second hottest month since records began in 1864, said MeteoSuisse in its June bulletin, with the national average temperature surpassing the norm by 3.3 degrees.
Even if temperatures go down in the coming weeks, summer 2017 will still be one of the hottest ever.
However with more warm, sunny weather predicted for at least the next two weeks, it's possible that this year's summer could surpass even the hot years of 2003 and 2015.
“We can't exclude the possibility that this summer will take first place following the conditions in late July and August,” MeteoSuisse meteorologist Marianne Giroud told news agencies.
Temperatures are expected to rise above 30 degrees again in the next few days, with some rain and storms likely towards the end of the week.
The warm weather continues this week. Source: MeteoSuisse