The annual and seasonal climate trends are visualised for the stations of the Swiss climatological network. The graphic charts show how the temperature and precipitation have changed for different periods. The illustration of trends at the stations also allows us to make conclusions about different regional and seasonal developments.
Trends at meteorological stations
Changes in temperature and precipitation can be illustrated for the 29 stations of the Swiss national basic climatological network (Swiss NBCN) for 14 different periods. The precipitation trend can additionally be shown for 46 stations with long-term precipitation series.
Temperature change in the past 30 years
The map shows the temperature change in the past 30 years for the locations of the climatic network, in each case indicated as change in °C per decade. The greater the trend value, the larger the circle is. Increases are shown in red, decreases in blue, with solid circles representing a statistically significant trend. The graphic chart illustrates the registration of a significant rise in temperature at all stations. For example, the value for Basel (in the North-West) is 0.42 (status date: 2014). This means that the temperature has increased by 0.42 °C every ten years from 1984-2013.
North-South cross-section of the change in precipitation during the past 50 years
In the North-South cross-sections, the stations are shown by altitude and distance from the Alpine divide. The change in precipitation during the past 50 years is indicated in percent; increases are shown in green, decreases in orange. The graphic chart illustrates a rise in precipitation at most stations in the central part and in the Canton of Jura. Decreases were in part also recorded along the Alpine divide. The rise (4.3% per decade) is only statistically significant at one station. The values recorded at the stations are additionally depicted by altitude and change. The black trend line shows tendency toward increasing amounts of precipitation at lower-lying stations (up to 700 metres above sea level), while decreases were registered more often at stations located between700 and 1500 metres above sea level.
The method of least squares is used for the trend calculation of the temperature, and the Theil-Sen equation for the precipitation. The levels of significance were estimated with the non-parametric test according to Mann-Kendall.
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