The weather in Zurich is unique because of the city's special geography. Zurich is situated at the Lake Zurich in a basin closed in by hills from all sides. This creates a microclimate with a quite often occurring thick layer of fog above the valley and winds from the west that bring more rain to the region compared to other places in the vicinity. The "Bise", a local wind from the east and northeast, keeps temperatures lower than would otherwise be expected. In general, the weather in Zurich is similar to that in the south of Germany.
If the average temperatures from January to December are transcribed into a climate chart, the resulting symmetrical curve shows only a mild incline like a low hill. Starting in January, the coldest month of the year, temperatures lie between 5° below zero and 5° Celsius. In February, the weather in Zurich is slightly warmer. December is similar in temperature and amount of rainfall.
In March, the average maximum temperature rises above 10° Celsius and there is already a little more precipitation than in winter. The curve climbs and temperatures reach an average maximum of 15° Celsius in April, with even more rain. The warmest month of spring is May when temperatures can reach a high of 20°.
In the three months of summer, the weather in Zurich is very pleasant, although in this season the highest amount of rain falls. The warmest month is July, where the average temperature is 17,6° Celsius. Usually it gets warmer during the day. At least 25° Celsius can be expected in the summer months and bathing is a very popular pasttime from June to August. The average temperature in the Lake Zurich is about 21° Celsius. Extreme heat is rather unusual. On average there are only about three really hot days in a year.
In September, there is still quite a lot of rain, but the amount decreases in October and November while the temperatures still stay mild which makes these months perfect for hiking and mountain climbing.
All in all, it can be said that the weather in Zurich is moderate. The "sea of fog", as it is called by locals, and the strong winds - phenomena which are caused by the city's special geographical location - keep the temperature lower and the weather wetter than in other big European cities like Paris, Rome or Madrid. On the other hand, there are no extremes. The summers are mild and pleasant. In winter, snow can be expected, so skiing and other winter sports can be enjoyed.