Is a "hellish summer" really on the horizon? The weather forecast doesn't support this at all.

What will the weather be like in summer 2025? Several German-language media outlets have reported in recent days that the upcoming summer will be particularly hot or dry. Some even referred to it as the "summer of the century," a "summer of drought," or a "summer of hell."

It's true: Meteorologists regularly issue forecasts for the coming months. These predictions currently indicate a trend toward warm, dry weather. But you can't rely on them.

"Such forecasts should be treated with great caution," says meteorologist Stefan Scherrer of the weather service Meteo Switzerland. They are not necessarily intended for private users, but rather for specific, professional applications such as precipitation and runoff forecasts for water supply and agriculture.

Many government meteorological services—such as the British, French, and German—regularly produce forecasts for the coming month or three months. However, these are not conventional weather forecasts. This means that you can't predict exactly whether it will rain or shine on a given day. Instead, they are based on averages.

"For example, we can't predict whether there will be heat waves or heavy rainfall next summer," says Scherrer. Rather, the forecasts indicate the trend for average temperatures or average precipitation.

The European Earth observation service Copernicus collects such forecasts. All nine meteorological services whose calculations were included in the compilation anticipate a summer with above-average mean temperatures for almost all of Europe, according to Carlo Buontempo, Director of the Copernicus Climate Change Service (C3S).

For German-speaking countries , the C3S website predicts a temperature that is one to two degrees Celsius higher than the reference period of 1993 to 2016. The precipitation forecast is much less pronounced, with only a slight tendency toward dryness.

The problem with such predictions for a month or longer periods, however, is that they are extremely uncertain – even according to Copernicus.

Meteorologists have long known that they generally cannot trust forecasts extending beyond ten days outside the tropics. This is even more true for a period of three months. Precipitation is particularly difficult to predict. Media outlets that supposedly announce a once-in-a-century summer or a drought summer tend to ignore this uncertainty.

There is only one European region for which the summer temperature forecast, according to Copernicus, has a moderately high degree of reliability – and that is the southeast of the continent. There, one can be confident that the predicted warm weather will actually occur. Everywhere else, the forecast is of little significance.

One trigger for the sometimes sensationalist media reports about a supposedly dry summer could be the current drought in Germany. This spring, in many regions, it has rained less than ever since records began, or only rarely – especially in the north.

The situation in Switzerland is quite different. Currently, there isn't a single region in the country where the soil is dry. The forecast for early June, the beginning of meteorological summer, also doesn't predict a lack of rain: "The weather will be rather mixed next week, with showers and thunderstorms passing through," says meteorologist Scherrer. A heat wave is absolutely not in sight at the moment.