As any resident of the alpine nation will tell you, up until recently it felt like the weather in Switzerland would never escape the grips of heavy rain and cloud cover. Now, new data from the Federal Office of Meteorology (MeteoSwiss) has found that since the turn of the 20th century, climate change has led to more intense and frequent rain.
According to the data, on average the heaviest rainfall recorded every year is now 11 percent more intense than it was in 1901. The intensity of rainfall has increased in 91 percent of locations analysed by the government, with the biggest increases reported immediately north and south of the mountains and in northeastern Switzerland
Periods of exceedingly heavy rainfall now occur in Switzerland four times a year on average, 25 percent more when compared to the turn of the century. By contrast, the Alps themselves, French-speaking Switzerland and central and southern Ticino have not seen a significant increase in rainfall since 1901.
When analysing heavy rainfall events in Switzerland - those lasting between 10 minutes and five days - between 1981 and 2023, MeteoSwiss found that short bursts of rainfall between 10 minutes and six hours long have generally gotten more intense, while longer periods of rainfall have gotten slightly less intense.
The impact of rising rates of rainfall was thrown into sharp relief in late June and early July 2024, when rainfall led to a landslide which destroyed a section of the A2 motorway. Just a week later, rain and flooding led to the destruction of more infrastructure and the deaths of several people.
MeteoSwiss explained that the heavier rainfall can be blamed on climate change. “The reason: warmer air absorbs more moisture and sooner or later this falls back to earth as precipitation.”
They argued that while global weather patterns still have the biggest impact on rainfall, “the intensity and frequency of heavy precipitation is likely to continue to increase due to rising temperatures.” They concluded that the Swiss government and cantons will have to adapt infrastructure and policy to better deal with future serious weather events, made all the more severe by climate change.