Tropical night in the southwest: heat wave brings danger of thunderstorms!
On June 13, 2025, Lörrach will experience a tropical night with extreme temperatures and a risk of thunderstorms in southwest Germany.

Tropical night in the southwest: heat wave brings danger of thunderstorms!
It's really hot in southwest Germany at the moment! Especially in cities like Cologne, Düsseldorf, Aachen and Freiburg, residents have to be prepared for anything given the high temperatures and humidity. The German Weather Service warns that Saturday night will be a tropical night with temperatures not falling below 20 degrees. Before that, however, another heat wave is expected on Saturday, which will particularly persist in the west and southwest of the country. This makes the situation really hot and uncomfortable.
A tropical night like the one we are currently experiencing means that the lowest temperatures will not fall below 20°C between 6pm and 6am UTC. This is not only seen as unpleasant, but also as a health problem, particularly for older or sick people who are more affected by nighttime heat extremes. Such nights are the exception in German-speaking countries, but their frequency seems to be increasing, especially due to global warming.
Weather developments and risk of thunderstorms
The high heat load is expected to continue to increase. From Saturday afternoon, individual, sometimes severe thunderstorms can be expected in the west, northwest and over the mountains in southern Germany. These thunderstorms could be associated with local heavy rain, which could further aggravate the situation. So it's worth always taking a look at the weather reports to stay well informed.
If you look at developments in recent years, you can see that such heat waves and tropical nights are no longer isolated cases. On average, tropical nights are increasing, which poses a relevant health challenge. While cities like Munich used to record around 1.7 tropical nights per year, this value has increased significantly in the last few decades.
The dangers of heat
According to the Federal Environment Agency, hot periods pose a significant health risk, especially when combined with tropical nights. In hot summers like 2018 and 2019, an estimated 15,600 additional deaths due to heat stress were registered in Germany. This problem particularly affects inner-city areas, where temperatures are often higher than in rural regions.
The projections show that heat-related mortality could increase in the future, with each one degree Celsius rise in temperature potentially causing over 5,000 additional deaths per year by mid-century. Of particular concern is that heat waves, a combination of hot days and tropical nights, pose health problems. Therefore, citizens should always pay attention to their health and take preventive measures if necessary.
The current weather situation represents an exciting but also challenging time for many. Looking at the forecasts, the focus is on the coming nights, especially those that will not fall below 20 degrees. If you plan to be outside during this time, you should make sure you have enough water and sun protection in order to get through the hot period without any health problems.
For further information and current weather reports, verlagshaus-jaumann.de can be visited, while additional explanations about tropical nights are available Wikipedia and on the health risks caused by heat can be found on umweltbundesamt.de.