Heavy rainfall is set to hit Switzerland on Wednesday, April 16, 2025, and Thursday, April 17, 2025, with the most severe impacts expected in the Wallis and Tessin regions. The Swiss Federal Government has issued multiple danger levels due to the threat of flooding, landslides, and significant snowfall in higher altitudes.
According to Meteo Schweiz, the weather service of the Swiss government, danger levels 3, 4, and 5 have been declared in Wallis due to continuous rain and snowfall. The highest level, danger level 5, applies to the upper Saastal and the southern Simplon area. Meteo Schweiz warns of an "extreme rise in water levels of rivers and lakes, floods in many places, and landslides and mudslides very likely."
In addition to the flooding concerns, heavy snowfall is anticipated in the high mountains, with predictions of up to two meters of fresh snow. This could lead to significant disruptions in road traffic, as authorities prepare for potential road closures and other restrictions.
The most intense rainfall is expected to occur between Wednesday afternoon and Thursday morning, with areas in the Wallis region, particularly the Mattertal, Saastal, Binntal, and Simplon areas, facing the brunt of the precipitation. In Tessin, the Maggiatal, Centovalli, and Onsernonetal are also forecasted to receive between 150 and 200 millimeters of rain, an amount that typically falls over the entire month of April.
As the storm approaches, meteorologists are advising residents to stay cautious. Simon Eschle, a meteorologist from SRF, indicated that while travel to the affected areas is possible, it is essential to monitor the situation closely. "In the affected areas, we must wait for the effects of the storms. There may be restrictions due to landslides or rivers overflowing their banks," he noted.
The rain is expected to persist until Thursday evening, April 17, 2025, with heavy thunderstorms also predicted for the western parts of Switzerland on Tuesday, April 15, 2025. These storms could bring high lightning activity and heavy rain from Tuesday afternoon until about 10 p.m.
In the high mountain regions, the snow line is expected to fluctuate between 1500 and 2000 meters. This means that while some precipitation will fall as rain, a significant portion will remain as snow, delaying its entry into drainage systems.
Authorities are advising residents to avoid riverbanks and steep slopes during this period and to heed warnings from the Federal Office for the Environment (BAFU) regarding potential flooding. The risk of mudslides is particularly concerning, as these can occur suddenly and without warning, posing serious threats to safety.
Looking ahead to the weekend, the weather is expected to ease slightly, with temperatures rising and occasional sunshine. However, further rainfall is anticipated, especially in southern Switzerland, and more rain is expected in central Switzerland on Sunday, April 20, 2025.
Overall, the upcoming days present a significant weather challenge for Switzerland, particularly in the Wallis and Tessin regions. Residents are urged to stay informed and prepared as the situation develops.
