The cities of Zurich, Basel, Aarau and Schaffhausen are expected to see temperatures hitting highs of 31 degrees on Monday, along with Sion in the canton of Valais, according to Meteonews.
The mercury should climb to highs of 30 degrees in Geneva at the western extremity of the country and in Chur, to the east, in the canton of Graubunden, and in Lugano in the canton of Ticino, Meteonews said.
But it will become even warmer toward the end of the week, with seasonal records for heat to be tested in some regions.
The highs for Sion are forecast to reach 35 degrees on Friday and 37 on Saturday.
Mixed into the picture is the likelihood of thunderstorms on Wednesday, with the possibility of hail in some regions.
An anti-cyclone centred in the northwest of Europe is influencing the weather in Switzerland and other countries, such as France, where warnings have gone out to people vulnerable to the heat, especially the elderly and small children.
The warm weather is expected to continue into next week.