Climatic forecasts
This is how heat waves will increase in our cities
Switzerland suffocates and the heat waves are increasing at a disturbing rate. By 2060, some regions may know up to 40 days a year above 30 degrees.
Of the heat wavele have been triggered for several days in a large part of Switzerland. When the temperature exceeds 30 degrees, the risk of circulatory problems increase, especially in pregnant women, young children, the elderly and the sick. The problem may intensify in the future. The number of heat waves continues to increase, as demonstrated by the example of seven Swiss cities.
Geneva
The Genevans are used to heat, as demonstrated by the long series of temperature surveys made since 1864. They had to face even higher temperatures in recent days. Three of the four hottest summers have been recorded in the last decade. By 2060, around 40 days of heat wave will become the standard in this region, a record greater than all other Swiss cities.
Zurich
The example of Zurich perfectly illustrates the increase in heat wave in Switzerland in recent decades. Heat peaks occurred occasionally, as in 1911 or 1947, but they were systematically followed by cooler periods. The situation has evolved from the mid -1970s, and since then, the number of heat waves increased continuously. Today, on average, the temperature exceeds 30 degrees twelve times a year.
It may seem little. In reality, this represents much more for many inhabitants of Zurich and is explained by the location of the Flunten measurement station, located on the Zurichberg, at an altitude of 570 meters. The temperature noted at this location often does not reflect that of the city center, located below and more urbanized. At the Stampfenbachstrasse, for example, there are an average of four more days of heat each year, compared to Flincern.
Such differences also exist in other cities. None of the sites of Weather (Federal Office for Meteorology and Climatology) with long series of measurements is not located in the city center. It is in this context that theUrban heat island effect appears. Dense urban areas store heat during the day and release it only slowly. The inhabitants of the city centers therefore suffer even more days of heat wave.
Basel
Basel has always experienced slightly higher temperatures than most other Swiss regions. This is mainly explained by the location of the city at a rather low altitude of 260 meters. Thus, even the Meteorological Station of Binningen, located on the outskirts of the city, has recorded almost every year heat wave since 1897.
However, the recent increase is significant. It will continue, as we observe in all other cities. According to Confederation’s forecasts, Basel will experience an average of 28 days of heat wave per year by 2060. Due to the temperatures that increase, the summer season now extends from May to September. According to Andreas Fischer de Météosuisse, “from 2060, the average temperature of September will be at a similar level or higher than that which we know today in June”.
Berne
The standard is even more marked in Berne-Zollikofen, where some years spent had no day of heat wave. But this has not occurred since 1997. As in many other regions, the record dates back to theSummer 2003. It could be beaten in 2025. June 2025 It will remain in history as the second hottest month ever recorded since the start of temperature statements. We have rarely experienced such a series of heat waves. And generally, temperatures are even higher in July and August.
Lucerne
In Lucerne, evolution follows a scheme comparable to that of many other cities. For decades, the average number of heat waves in summer remained relatively stable, apart from a fleeting period of heat in the 1940s. The sharp rise began in the 80s and continues until today, with a trend that should continue in the future.
Saint-Gall
Compared to other cities, Saint-Gall is a rather fresh place. Temperatures still remain two to three degrees below the Swiss national average. The difference is even five degrees compared to Geneva or Basel. This phenomenon is explained by the altitude of the city and by the location of the weather station. This is 776 meters above sea level, on a green hill overlooking the city center. The heat waves are rare there, but in recent years they have become more and more frequent.
Lugano
It is difficult to conceive today, but Ticino has also lived in the past whole years without the thermometer exceeding 30 degrees. Today, having at least fifteen days of heat wave has become normal in summer, even in Lugano. In 2003, the Monti measurement station recorded 56 days of heat wave.
The days of heat wave therefore become more frequent in all regions of Switzerland, from Saint-Gall to the east in Geneva to the west, from Basel to the north in Lugano to the south. THE Climatic scenarios of the Confederation reveal that if warming continues at this rate, the number of heat waves in certain Swiss cities will double by 2060 and triple by 2085.
“In the absence of a international climate policythe heat wave will multiply in the years to come. The temperature often exceeds 30 degrees for several days in a row, which causes an overall increase in heat waves in the low altitude regions. With climate change, these will be more frequent, more intense and longer, ”warns the expert.
This is what an analysis of temperature data reveals. In the past fifty years, the heat waves of three to seven days have already won 3.8 degrees on average across the country. According to Météosuisse, this evolution constitutes a manifest index of climate change of human origin. Even if international climate policy was reinforced and warming slowed down, Switzerland would face an increase in heat wave in the coming decades.
Translated from German by Emmanuelle Stevan
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