During the hot weekend, the German Weather Service in Cottbus measured an all-time temperature record of 39.2 degrees on Sunday. That was not only the highest value of the weekend in Germany, but also the highest value ever at this measuring point. On July 29, 1921, 38.9 degrees were recorded, as the DWD further announced on Twitter.

In Berlin, too, temperatures at the weekend climbed to levels well over 30 degrees, which were previously unattainable this year. The DWD drew attention to the exceptional heat stress on Saturday and Sunday with an official heat warning for Berlin and parts of Brandenburg.

The midsummer weather drove many people to lakes or to the outdoor pool on Saturday. According to DWD information, the highest values ​​at the Waghäusel-Kirrlach measuring stations on the Upper Rhine (Baden-Württemberg) and in Bad Kreuznach (Rhineland-Palatinate) were registered in the late afternoon with 37.1 degrees. Two people died in swimming accidents in Berlin.

In the Berlin-Brandenburg region, an official heat warning from the DWD applies in view of midsummer temperatures well over 30 degrees until Sunday, 7 p.m. As on Saturday, the federal capital, Potsdam and other districts are again expected to experience severe thermal stress, the weather service said on Sunday morning on its website.

In addition, the experts in many places again drew attention to the unusually high level of UV radiation and the need for appropriate protective measures.

The DWD had already warned of severe heat stress in the capital region on Saturday. Above all, older people and other people with a tendency towards an unstable circulation are considered to be particularly at risk in such heat. On Sunday, there were even warnings of extreme heat stress in Offenbach in the Upper Rhine area.

But the heat chaos does not threaten everywhere and not all day on Sunday. After a hot start to the day, according to the forecast, more and more clouds are likely to swell from the afternoon, especially over the middle, in the south-west German mountains and in the Alps. Local thunderstorms and severe weather are possible.

The astronomical and also the calendar start of summer is on Tuesday (June 21). Then the sun reaches its northernmost point above the earth and at noon it reaches its highest point of the year.

According to the forecast, on this first day of summer there will be cumulus clouds and local showers and thunderstorms, especially in the south and south-west. In the northern half it will probably be 22 to 28 degrees warm, on the coasts it will stay a little cooler. To the south it will probably be hot again with 27 to 33 degrees.

Due to the intense heat and lack of rain, there is still a high risk of forest fires in some parts of Germany. How great the danger is was shown at Treuenbrietzen between Potsdam and Lutherstadt Wittenberg. The situation there came to a head on Sunday night. The district administrator of the Potsdam-Mittelmark district had declared the disaster, said a fire department spokesman in Brandenburg/Havel.

Lifeguards warn of the dangers of swimming in unguarded waters. The spokesman for the state association of the German Life Saving Society (DLRG), Daniel Keip, told the German Press Agency: “We find again and again that bathers and swimmers overestimate their own abilities”. Water has no bars, that is sometimes forgotten, said Keip. And the further away the bathing spots are from other people, the further away the next help is.

Three people died in swimming accidents in Brandenburg on the Pentecost weekend. According to Keip, many such accidents happen out of carelessness, because people have the impression that they are efficient. The lifesaver recommended an old rule for bathing and swimming in sweltering heat: “Cool down before bathing, get used to the water temperature, don’t overstrain yourself.” Sunbathing for half an hour and then going straight into the water to cool down can put a strain on the circulation, Keip warned .

According to the fire department, a 17-year-old was reported missing on Saturday evening at Weißen See in the Pankow district. The rescue workers found the teenager after a 20-minute search in the lake and initiated resuscitation measures – according to a spokesman without success.

About an hour and a half later, the fire brigade was called to the airport lake in the Tegel district because of a missing 59-year-old. Divers managed to find the man floating in the water, but resuscitation measures were also unsuccessful in this case.

The man had probably been floating in the water for several hours and had gone under – apparently unnoticed by other bathers. It was initially unclear how the two swimming accidents came about.

There were many boats, stand-up paddlers and kayaks on and in the waters between Berlin and Potsdam, and the upper decks of excursion boats were well filled. Berlin’s outdoor pools saw an extraordinary rush on both days – the queues, some of which were many meters long, often required patience and good nerves.

According to a dpa reporter, for example, before the summer pool at the islander, the first queues formed early on Sunday morning and grew rapidly. At the entrance, security forces tried to keep the large crowd in order. In other pools, too, the number of guests was well above average.

With a view to the hot weekend, the Berlin baths had asked bathers to book their tickets in advance in the online shop, which guaranteed entry. The server for the online shop could not withstand the exceptionally high demand, as spokesman Matthias Oloew said on Sunday. On Saturday alone there were around 260,000 inquiries to the shop.

“That’s a multiple of what we sold as a long-term average of tickets for such a hot weekend. Therefore, this high pressure of inquiries was not to be expected,” says Oloew. After problems on Saturday, the shop went down again on Sunday, according to the information. Tickets for the outdoor pools can initially only be obtained at the pool cash desks, the spokesman said.

On Saturday there were many day trippers, many trains were canceled, were late or were very full. The railway subsidiary DB Regio announced on both days for trains of several regional lines such as RE1 and RE3 via Twitter, for example, that “due to the exceptionally high number of passengers” no more people could board and no bicycles could be taken.

When asked about the background, a railway spokesman said that the 9-euro ticket was popular and meant that more people were traveling by bus and train. In the Berlin and Brandenburg region, construction sites and a slightly higher level of sick leave are also currently affecting the quality of regional transport.

According to scientists, the increase in heat waves and droughts is a direct result of global warming. The intensity as well as the duration and frequency of these phenomena are increasing.

Climate change is leading to earlier heat waves, explained Clare Nullis from the World Meteorological Organization (WMO) in Geneva.