Approximately 7500 sirens (of a total of around 8200 sirens for alerting the public), which are distributed throughout the country in populated areas, only sound a general alarm. 4700 of these sirens are stationary, located on roofs (or pylons), and 2800, are mobile; which can be attached to vehicles and are intended for alerting dispersed settlements. There are an additional 700 multi-function sirens located near dams, which in addition to sounding a general alarm can also activate a flood alert.

The annual siren test takes place in Switzerland on the first Wednesday of February. It is organised by the Federal Office for Civil Protection (FOCP) in cooperation with the cantons, communes and dam operators. At this time, not only general alert sirens but also water alert sirens are tested to see if they are in working order. People are given advance notice about the siren test on television broadcasts as well as in the newspapers. The siren tests do not require the population to take any special measures.

The National Emergency Operations Centre (NEOC) coordinates activities during a state of emergency (e.g. in the event of increased radioactivity, chemical accidents, dam breaks, satellite crashes, natural disasters etc.). MeteoSwiss becomes involved in the event of dangerous weather events, the Federal Institute for Snow and Avalanche Research in the event of avalanche danger and the Swiss Seismological Service in the event of earthquakes. The cantonal authorities and the NEOC have the authority to sound their sirens when they deem it to be necessary. The NEOC also acts as a national reporting and assessment centre when a natural hazard or technical incident occurs.

According to the authorities it has been possible since 2011 to rapidly alert the population throughout Switzerland in the event of natural hazards. When a natural hazard is rated as “high” or “very high”, i.e. reaching levels 4 or 5 on a danger scale of five standardised levels, the specialised federal offices may issue instructions to broadcast warnings via radio and television. The warnings contain brief information about the type, time and location of the expected hazard, as well as non-binding recommendations on what to do and additional sources of information. A warning can be issued as limited or indefinite. In the event of indefinite warnings, an all-clear must be issued once the hazard has ceased to exist.

A description of the two alarm signals is provided on the last page of all phone books, on teletext on Swiss television, page 662 (German and French) and page. 672 (Italian) as well as on the Internet.