Every year, Switzerland tests its apocalyptic-sounding sirens on the first Wednesday of February. On 5 February 2025, over 5,000 sirens sounded throughout Switzerland during the siren test. 99% of the sirens tested worked perfectly, reported the authorities. As part of the test more than 12 million push notifications were sent from the Alertswiss app during the course of the day. Several cantons also tested their mobile sirens.
Sirens were installed across the country starting in 1936 and testing was introduced in 1970, before becoming compulsory in 1988.
Switzerland has roughly 5,000 fixed sirens and 2,200 mobile ones. 600 of which are used for flood warnings. Fixed alarms can be activated centrally by cantonal police.
Outside of test times, when the sirens sound, you are required to listen to the radio, follow directions from the authorities and inform your neighbours. Informing neighbours is important because some may not hear the sirens, or may not understand the instructions.
In addition to sirens, there are alert apps. The national Alertswiss app sends alerts, warnings and information on dangers and hazards directly to users phones. The free app is available for iOS and Android.
If you hear a flood siren, which has a distinctive deep sound lasting for 20 seconds repeated 12 times, then you should immediately leave the danger zone and follow the instructions of the authorities. Flood sirens are only used in risk zones near dams. Click here to hear a flood siren. Click here to hear a general siren.
The following advert, warning of the testing, features a sheep and a long list of Swiss icons.
More information on how to be prepared can be found on the government website Alert Swiss or X(Twitter).
More on this:
Government press release (in French) – Take a 5 minute French test now
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