The annual course series allow the comparison and ranking of current temperature, sunshine and rainfall measurements against their long-term averages (norm values). The daily temperature, sunshine and precipitation development since the beginning of the respective series of measurements can be illustrated graphically for the stations of the Swiss climatological network. The graphic charts for the current year cover the values of the past twelve months; they are updated daily.
Annual course series
Temperature evolution in Altdorf, 2020/2021
The graph of the course series for the past 365 days shows the temperature deviation from the average homogenous daily mean of the normal period from 1991-2020. Red bars indicate warmer, blue bars colder days. It can be seen at a glance that from the end of April to the end of May 2020 it was colder than the long-term average. Thereafter, June was significantly warmer. Based on the additionally shown standard deviation (dashed line) as well as the highest and lowest temperatures ever measured (gray values), the temperatures of 2020/2021 can be classified. This clearly shows that the high temperatures in January and February 2021 as well as in June 2021 were just at or even above the highest values ever measured before. The fact that it was slightly cooler than normal in the past twelve months is also shown by the temperature mean of 10 °C, which was 0.2 °C below normal.
The graph of the course series over recent years shows the temperature deviation from the average homogenous daily mean of the normal period from 1991-2020 (black line). Here too, red bars indicate warmer, blue bars colder days. It is easy to see why 2020 is one of the only slightly warmer years since measurements began in 1864. All months except February, April and September (warmer) and June (colder) show hardly any deviations from the standard period 1991-2020. The range of all monthly mean temperatures measured so far is shown as a light gray bar (from minimum to maximum). One can quickly see that the monthly mean temperature in February 2020 only just missed the maximum of all February means recorded so far. With 10.8 °C the annual mean temperature in Altdorf in 2020 was 0.6 °C above the norm (1991-2020) of 10.2 °C.