Long-term data series for temperature, precipitation and sunshine duration are available at MeteoSwiss. For several locations, these date back as far as 1864 (Swiss National Basic Climatological Network). These long-term data series are extremely valuable for understanding climate change both in the past and the present. To ensure that man-made changes such as station relocations or the use of new measuring instruments do not have a confounding influence on the results, the measurement data are extensively checked for measurement errors and temporal homogeneity before being analysed.
Statistical methods can be used to derive values from the measurements at the individual stations for any location in Switzerland where there is no measuring station. This makes it possible to create maps displaying the changes in temperature, precipitation and sunshine duration for the whole of Switzerland. In addition, they can be used to calculate mean values for individual areas.
Clear signs of warming in the country as a whole
The annual mean temperature has risen by around 2°C (linear trend) in Switzerland since 1864. This is equivalent to an increase of between 0.08 and 0.15°C per decade. The increase was somewhat greater north of the Alps than in the south. Aside from this, the annual mean values show no major geographical differences in the warming trend. The trend towards warmer temperatures is statistically significant in all parts of the country. According to current global climate research, it is clear that this trend can only be explained in terms of the human contribution to the increase in global greenhouse gas concentrations.