What kind of weather to expect in Switzerland in October
In October, the weather is very unpredictable. In the mountains, temperature are quite chilly, with daytime temps around 12 - 16 C and nighttime temp from 0 - 5 C.
October used to be full of cloudy and rainy days. But in recent years, we've had longer stretches of sunny, if chilly, days. It's not unusual to have the occasional snow storm in the mountains, which closes down trails for a couple days. But often it warms up again and the snow melts. There's usually not enough snow for ski season until at least early December.
In any case, it's important to check the relevant websites for current trail conditions and lift operating status. These can close last minute due to poor weather.
For weather forecasts, we recommend MeteoSwiss, which is the official Swiss weather service. They also have a mobile app. We also like Search.ch which is a bit simpler.
Go check out my guide for the best free things to do as well as itineraries and travel tips to make your trip unforgettable.