La chaleur fait une pause

The third heatwave of the summer has finally come to an end after several days of temperatures exceeding 30 degrees Celsius, according to Swiss weather reports. The early summer heatwave, which began in late May, marked one of the earliest and most intense periods of extreme heat this year. Now, with the arrival of a cold front on Sunday, the air over Switzerland is set to shift, bringing cooler conditions and more moderate temperatures. This change comes just weeks into the summer season, raising concerns about how many more hot days might follow. The coming week will see temperatures gradually returning to average levels, though they remain higher than typical for this time of year. During the day, temperatures are expected to range between 20 and 25 degrees Celsius, while nighttime lows will drop to between 10 and 15 degrees. These conditions, although milder compared to recent weeks, still feel cool to many residents who have grown accustomed to the relentless heat. According to historical data from 1991 to 2020, these temperatures align closely with the July averages for much of the country. Meteorological forecasts suggest that the hottest part of the year, traditionally known as the “Hundstage” or dog days, may return later in the month. These typically occur between late July and early August, when temperatures often reach their peak. However, whether this pattern will repeat this year remains uncertain. Some experts warn that the number of extremely hot days could continue to rise, especially given the increasing frequency of such weather events in recent years. Weather maps from the European Centre for Medium-Range Weather Forecasts indicate that the upcoming week will feature temperatures that are either near normal or slightly below average. This cooling trend is expected to last through the middle of the week, offering some relief to communities that have endured prolonged periods of high heat. Nevertheless, the data also shows that the temperature anomaly will likely persist beyond this period, with further warming anticipated in the following weeks. Comparisons with past summers highlight the growing severity of heatwaves. For example, in Bern, the threshold of 30 degrees Celsius was exceeded 26 times so far this year, surpassing the annual average of nine recorded in the 1991–2020 period. In Basel, the figure is even more striking, with 34 days already classified as hot. These numbers exceed even the record-breaking heatwave of 2003, during which Bern saw 32 and Basel 41 such days. Notably, the current summer has already produced more hot days in June and July than the 2003 season. Looking ahead, meteorologists predict that the trend of increased heat days is likely to continue. The forecast suggests that temperatures will remain above average throughout the remainder of the summer, potentially leading to another wave of extreme heat. This pattern is consistent with broader climate trends observed across Europe, where rising global temperatures have contributed to longer and more frequent heatwaves. As the weather shifts, local authorities and public health officials are preparing for the possibility of continued high temperatures. While the immediate outlook offers temporary relief, the long-term implications of these changing patterns remain a subject of ongoing study and concern. With each passing summer, the evidence of a warming world becomes increasingly clear, and the need for adaptive strategies grows ever more urgent.