Temperature data from all the automated stations of the SLF and from high-altitude (>1900 m) automated stations of MeteoSwiss are shown.
The air and snow surface temperatures are key factors when assessing avalanche danger, in particular when springtime conditions amid wet snow avalanches prevail. Air temperature is measured by all automated stations, but snow surface temperature is recorded only by the automated IMIS snow stations of the SLF.
The map shows the most recent available value for each station. If the most recent measurement was taken more than 210 minutes earlier, the station is greyed out and depicted without a value. Some of the depicted values originate from raw data that have not been checked or validated.
The temperature sensor is cloaked in a white housing in order to minimise the influence of radiation. At the automated stations of the SLF, the sensor is located up to 6 metres above the ground – depending on the snow depth. The snow surface temperature is calculated from the measured outgoing longwave radiation.
The automated stations of the SLF are solar powered, so that there is insufficient energy to allow active ventilation of the air temperature sensor. On fine-weather days without any wind, the sun raises the temperature of the housing and, around midday when such conditions prevail, the measured air temperature is too high.