According to the preliminary balance sheet of the German Weather Service (DWD), the summer of 2023 is also one of the series of overly warm summers in Germany. With an average temperature of 18.6 degrees, this year's summer was 2.3 degrees above the value of the internationally valid reference period 1961 to 1990, reported the DWD for the evaluation of its around 2000 measuring stations for the months of June to August.

Compared to the current and warmer comparison period from 1991 to 2020, the deviation was exactly one degree. "Overly warm summers have been measured in Germany for 27 years now," said DWD spokesman Uwe Kirsche. "Again we can experience climate change live."

A summer of wet facts

According to DWD information, the summer this year was characterized by large fluctuations: there was tropical heat, but also early autumn fresh temperatures. On June 3rd, the nationwide summer low of minus 0.7 degrees was recorded in Sohland on the Spree. As June progressed, however, it became noticeably warmer - even exceptionally warm in southwest Germany.

It is possible that those who mainly needed an umbrella in the past few weeks and who complained about rather cool temperatures, don't really remember the hot days in July, which made people sweat a lot - especially on July 15th at 38, 8 degrees in Möhrendorf-Kleinseebach in Bavaria. And in mid-August, after a rather autumnal, cool start to the month, summer again showed itself with a decent rise in temperature, but also with very humid air.

In general, the summer of 2023 was not stingy with wet facts: At around 270 liters per square meter, a good tenth more precipitation fell this summer than the average for the reference period 1961 to 1990. During the summer there was precipitation throughout the country: it reached its peak in August with sometimes heavy rain and hail storms. Summer in the southeast came to an end with constant rain and increasing risk of flooding. Up to 600 liters of precipitation per square meter were measured directly in the Alps over the course of three months. In Bad Berneck in the Fichtelgebirge, the highest daily amount was recorded during a storm on June 22 with 120.7 liters of precipitation per square meter.

Sunniest in the foothills of the Alps

But despite all the rain and thunderclouds: the sun made its way in the summer of 2023 as well. At 720 hours, the sunshine duration exceeded the target of 614 hours for the comparable period 1961 to 1990 by around 17 percent. June was even the second sunniest since measurements began. The sun shone the most with more than 800 hours in the foothills of the Alps and on the border with Switzerland.

If, despite these measured values, many people find it difficult to believe that the summer of 2023 was also too warm, this is due to personal experiences and feelings, such as a holiday spent in constant rain, says Andreas Matzarakis, head of the DWD's Center for Medical Meteorological Research . "This makes it easy to mislead. One also speaks of warm or cold weather," said Matzarakis of the German Press Agency. It's all highly subjective - and that's why it's important for the scientific assessment of the summer to be based on exact measurements.

"Being in and in the midst of climate change"

According to a statement by the Potsdam Institute for Climate Impact Research (PIK), the summer balance sheet underscores "that we are in the midst of climate change". The summer was not only warmer than the long-term average, but also wetter. Nevertheless, the deeper soil layers in many regions of Germany, especially in the east and south, are still unusually dry, explained the PIK hydrologist Fred Hattermann. This year's precipitation could not compensate for the precipitation deficit that has accumulated over the past few years. Not only that: "Due to the fact that this summer was also warmer than average and the radiation has also increased sharply, the water requirements of the vegetation are constantly growing, and we would have to get more precipitation every year to compensate for this."

The expert also emphasized: "With the onset of El Niño, which leads to above-average surface temperatures in the southern Pacific, there is a risk that we will see further extremes next year and that global warming may exceed 1.5 degrees for the first time."

The United Nations (UN) describes climate change as long-term changes in temperatures and weather patterns that have been "mainly due to human activities" since the 19th century - these, according to the UN, are primarily the burning of fossil fuels such as coal, oil and natural gas .