Test day: first Wednesday in February

Every year, on the first Wednesday in February, all sirens across Switzerland are tested. The public is notified beforehand through announcements on the radio, on TV and in the press. The general public is not required to respond in a particular way or take protective measures, but simply requested in advance to excuse the inconvenience caused by the noise of the sirens.

Two alarm signals

At 1.30 p.m. the ‘general alert’ signal is sounded throughout Switzerland. This is a regular ascending and descending tone, which lasts for one minute, and is repeated once after a two-minute interval. Where necessary, the sirens can continue to be tested until 2 p.m. From 2 to 4.30 p.m. (at the latest), the ‘water alert’ signal is tested in those areas that are close to dams. It consists of twelve low continuous tones lasting twenty seconds and repeated at ten-second intervals. The function of a total of 7,200 sirens is tested. 

Responding correctly to an alarm

If the  ‘general alert’ signal sounds outside of the announced siren test, this means that there may be a danger to the population. In this case, the population is asked to listen to the radio, consult the Alertswiss channels, follow the instructions of the authorities, and inform their neighbors. The ‘water alert’  means that people should leave the endangered area immediately. Further information and rules of conduct can be found on Alertswiss and on teletext, page 680.