Record temperatures nearing 40 degrees Celsius were reported across parts of Germany on Wednesday, marking the hottest day of 2025 so far.

Meteorologists forecast thunderstorms later in the evening that are expected to bring relief and lower temperatures.

Preliminary data from the German Weather Service (DWD) confirmed Wednesday as the hottest day of the year. Final temperature readings for specific locations are expected to be available later.

The weather service warned of a “localized risk” of severe weather as thunderstorms hit parts of the country.

On Tuesday, the DWD said it had recorded the highest temperature of the year to date: 37.8 degrees in Kitzingen, Bavaria, according to preliminary measurements.

The all-time heat record for Germany was measured on July 25, 2019, at 41.2 degrees Celsius at the DWD weather stations in Tönisvorst and Duisburg-Baerl, both in the western state of North Rhine Westphalia.

Health risks

Health experts noted that young children and older adults are especially vulnerable when temperatures rise.

As people age, their ability to regulate body temperature slows, and they have fewer sweat glands, meaning the body’s natural cooling system is less effective.

Babies and young children are also at risk of dehydration and have lower sweat production.

In 2023 and 2024, an estimated 3,000 people are believed to have died from heat-related causes each year, according to the Federal Environment Agency and the Robert Koch Institute.

Most of these were individuals over the age of 75 with pre-existing conditions such as dementia, cardiovascular disease, or lung conditions.