A study by MeteoSwiss says the country in 50 years will benefit from 65 to 80 days of summery weather in the “plateau”, the region north of the Alps, instead of the current 50 days.
The national weather office’s report says global warming will transform the region’s climate into a Mediterranean one.
Valleys in the Jura will gain an extra month of summer by 2060 and many Swiss cities will develop Italian-type temperatures, the report says.
“In many areas of the plateau the temperature levels should correspond to those currently found south of the Alps (in the canton of Ticino),” MeteoSwiss says.
In less than 50 years time, Geneva will be as hot as it now is in Milan, according to the predictions.
Basel and Neuchâtel, meanwhile, will have temperatures as high as those in Lugano and Locarno, typically the warmest spots in the country, the report says.
In Ticino, near lakes such as Maggiore, the climate will become similar to that currently enjoyed in Florence and Rome.
The weather office expects heat waves to become more frequent, with periods of extreme dryness during the summer, although this is unlikely at other times of the year.
For skiers, the warming trend means less snow in the mountains in the winter.
The average number of days of snowfall in Alpine areas is forecast to drop to 80 days a year from 110 days in many mountain areas.
The weather experts also expect less of the white stuff in the plateau, with just 10 days a year of snowfall compared to an average of 30 today.
Could all this be wildly inaccurate?
MeteoSwiss says its prediction is based on sophisticated climate modelling based on complex calculations made by powerful computers.
However, the models represent a simplified version of the actual climate, so long-term forecasts are uncertain, the weather office acknowledges.