safe link:
https://www.meteoswiss.admin.ch/home/climate/the-climate-of-switzerland.html
Explanation:
The Climate of Switzerland
Switzerland's climate is heavily influenced by the Alps as well as by the Atlantic Ocean. Winters in the northern plateau are mild and damp, whereas higher altitudes experience arctic temperatures. At altitudes above 1200-1500 metres or so, precipitation in the winter falls mainly as snow. The south side of the Alps is strongly affected by the Mediterranean Sea, and so winters there are mild and the summers warm and humid, and sometimes hot. All along the Alpine ridge there are frequent thunderstorms in the summer.
Climate can be defined as the totality of typical weather processes in a region over a given period of time. The climatic portrait of Switzerland is formed mainly as a result of the geographical position of the country and its complex topography. The geographical location determines what kinds of weather are predominant, while the topography gives rise to regional differences and special climatic conditions within Switzerland.
Climate portrait of Switzerland
The climate of Switzerland is heavily influenced by the Atlantic Ocean. On prevailing currents from westerly and northwesterly directions, mild, humid sea air ends up in Switzerland. In summer, this has a cooling effect, and in winter a warming effect, and most areas enjoy an adequate amount of precipitation throughout the year. The Alps act as a prominent climatic barrier between northern and southern Switzerland.
Southern Switzerland is mainly affected by the Mediterranean Sea, where the climate differs from that of the north, most notably in its significantly milder winters.
Enlargement: Flow directions over Switzerland
Frequencies of flow directions over Switzerland for every day of the year. W: Westerly, NW: Northwesterly, N: Northerly, NO: Northeasterly, O: Easterly, SO: Southeasterly, S: Southerly, SW: Southwesterly flow, T: Low pressure area directly over Switzerland, H: High pressure area directly over Switzerland. The analysis includes data for every day of the year.
Further information on weather events of the past and on Switzerland's climate:
Climate normals
Monthly and annual reports
Monthly and annual reports
Annual course series for temperature-sunshine-precipitation
Dry in the inner Alpine valleys
In addition to their prominent role as a climate barrier between north and south, the Alps also generate several different climate regions. One of these is that of the inner Alpine valleys, which have a distinct climate of their own as they are shielded from precipitation from both the north and the south. The consequence of this is the relatively dry conditions throughout the year. Â
Typical examples of these dry valleys are the Canton of Valais in the south west and the Engadine in the south-east of Switzerland. In the Valais, the average precipitation is between 500 and 600 mm per year, depending on the particular area, while in the Engadine it is between 600 and 700 mm per year. In contrast, the northern Alpine foothills, the Alps and southern Switzerland, annual precipitation volumes of around 2000 mm are the norm. In the northern plateau, the average amount is around 1000 to 1500 mm per year. Around double the amount falls in summer compared to in winter.
Further information on precipitation distribution in Switzerland:
Climate normals
Climatology of heavy precipitation
Snow in winter
Starting at an altitude of 1200-1500 m above sea level, precipitation during winter predominantly falls as snow, such that the area is often covered by a solid layer of snow for weeks, and even months at higher altitudes. Snowfall is relatively rare in the low-lying areas of western Switzerland (greater Geneva area) and northern Switzerland (greater Basel area) as well as in the lowland in the southern tip of Switzerland. In these warmer regions - mainly because of their low elevation - completely snow-free winters are not uncommon.
Further information:
Specialties of the Swiss climate
From Arctic to Mediterranean
Swiss records and more on that link
Climate diagrams and normals per station