The Swiss Permafrost Monitoring Network PERMOS documents the state and changes of permafrost in the Swiss Alps based on field measurements of ground temperatures, electrical resistivities and rock glacier velocities. A general trend of permafrost warming and degradation in the Swiss Alps is documented by more than 20 years of data, which also show some spatial variability related to site characteristics and shorter-term variations due to meteorological conditions. The mean annual air temperature in the hydrological year 2021 (October 2020 to September 2021) was 0.3 °C above the long-term mean 1981–2010, and it was the lowest since 2013. The hydrological year 2021 was characterized by a mild winter with a long-lasting snow cover, a cold spring, a wet summer and a dry and sunny autumn. [...]