The reliability levels are explained as follows:
A reliability of under 30% is considered to be low. The predicted weather type is the most probable of all possible weather scenarios. However, when planning weather-dependent activities, reliance on this forecast is not recommended. It is recommended that you consult later forecasts.
A reliability of between 30% and 70% is considered to be average. The forecast may serve as a basis for planning, but you should also prepare for alternative weather.
A reliability greater than 70% is considered high. This forecast can be taken at its word. However, surprises are always possible.
MeteoSwiss also provides information on the probability of temperature and precipitation development in its forecasts.