Chiemsee before Weather Change: Sun on the Weekend, Then Thunderstorms and Rain

At Chiemsee, the weekend initially starts off friendly and mild. However, at the beginning of the week, the 3-day forecast indicates a clear change: Temperatures drop, while the risk of rain increases significantly – and thunderstorms are also possible.

For the period from Saturday, May 9, to Monday, May 11, 2026, this results in a classic pattern of "first early summer feeling, then setback": After a mostly pleasant Sunday, a noticeably cooler and wetter phase follows on Monday.

Saturday at Chiemsee: Friendly, but Occasional Drops Possible

Saturday (05/09) will be partly sunny, with light rain possible in isolated cases. The temperature reaches 19 degrees, with values at 8 degrees during the cooler hours. Notable is especially the combination of a high precipitation risk (80 percent) and a very low expected amount (0.1 l/m²): This suggests isolated, short showers rather than prolonged rain. In addition, 6 hours of sunshine are indicated.

Sunday Brings the Mildest Phase of the Weekend

Sunday (05/10) is considered the best day for outdoor activities in the forecast: more sun than clouds, 23 degrees during the day and 9 degrees in the cooler hours. The precipitation risk drops to 15 percent, with precipitation given as 0 l/m². With 8 hours of sunshine, it is also the sunniest day in the 3-day overview.

An interesting look at the climatological classification: The climate table used is based on measurements at climate stations from 2015 to 2020. For May, maximum values of 18 degrees and minimum values of 7 degrees are listed. The forecasted maximum of 23 degrees on Sunday is therefore clearly above this comparison value – as is the minimum of 9 degrees.

Monday: Weather Turns – Cooler, Wetter, with Thunderstorm Potential

On Monday (05/11), the weather situation changes significantly. Predominantly light rain is expected, and thunderstorms are also possible. The maximum temperature drops to 14 degrees, the minimum temperature is 11 degrees. At the same time, the precipitation risk rises to 90 percent, with the expected precipitation amount at 7.7 l/m². No sunshine hours are forecast for this day.

This means the daily high temperature drops from 23 to 14 degrees within 24 hours. The timing of the change is exactly in a phase when cold air incursions can repeatedly occur in Central Europe – colloquially, this is often associated with the "Ice Saints" around mid-May. Whether this actually develops into a multi-day cool spell cannot be reliably inferred from this short preview alone.

For thunderstorms, it also applies: A high probability of precipitation does not mean it will rain continuously. The German Weather Service describes the probability of precipitation as a model indication of how likely precipitation is during a period – not as an exact statement about duration and timing at every specific location. Especially with showers and thunderstorms, it can therefore vary greatly locally.

Conclusion

All in all, the weekend at Chiemsee is initially pleasant, before Monday becomes significantly more unsettled. Those planning excursions or longer tours will find the best conditions on Sunday – at the start of the week, rain gear and a plan B are advisable.