Today, around 5000 sirens will sound throughout Switzerland - they will be tested to ensure they are still working. The Alertswiss warning app is also being checked at the same time.
When and why are they tested?
The siren test takes place between 1.30 pm and 4.30 pm. The general alarm (regular ascending and descending wailing tone for one minute) and the water alarm in the zones below dams (twelve low continuous tones of 20 seconds) are tested. Last year, 99 percent of the sirens worked perfectly.
In each canton, a message is also triggered via Alertswiss. At the same time, the Federal Office for Civil Protection (Babs) calls on people to build up their own emergency stockpile. The Federal Office for National Economic Supply (FONES) emergency stockpile calculator can be used to calculate and check your own emergency stockpile. A revised version of the corresponding brochure will be available in mid-February.
What should I do if an alarm goes off?
If it is an announced test, you don't have to do anything. Otherwise: listen to the radio or find out about Alertwiss. The radio stations are also obliged to broadcast the authorities' instructions in the event of an alarm. This year, the test is taking place for the first time after the FM frequencies of the SRG stations have been switched off. Their radio signals will now only be broadcast via DAB+.
However, there is one exception, namely so-called emergency radio. This FM-based system, which is very expensive to maintain, enables radio reception in shelters. However, according to a Federal Council decision, it will no longer be operated.
The reason for this is that the Federal Office for Civil Protection assumes that short stays in shelters in the event of a disaster or war are more likely than staying there for weeks or months.
The water alarm means that there is an immediate threat to the population from a dam burst or similar scenario below a dam. In the event of a serious alarm, people must leave the endangered area immediately.
If there is a power failure or technical malfunction, the emergency meeting points will be notified of the event. The exact locations are shown on a federal map.
The Swiss siren network has been continuously developed over the last 80 years. Since 2015, they have been connected to the central, protected Polyalert system. They are normally triggered by the respective cantonal police.
At federal level, the National Emergency Operations Center can order the sirens to be activated in cases of increased radioactivity. A siren network in the modern sense has existed in Switzerland since the late 1930s.
Can sirens damage hearing?
There are upper limits for the sound: A maximum sound level of 118 decibels is permitted where people are present. But only if it is possible to leave the sounded room within 15 seconds. Otherwise you are exposed to 112 decibels. In the case of a water alarm, it is 104 decibels.
For comparison: in a disco, the volume must not be turned up to over 100 decibels. You should expose your ears to this volume for a maximum of two hours a week, otherwise there is a risk of hearing damage.
What were the most serious false alarms?
So far there have been two major false alarms in Switzerland. For example in Biglen BE in 1994. A false siren alarm led to around 60 firefighters being called out in the middle of the night for nothing. The cause was a technical problem.
In 1987, a civil protection officer in Brugg AG was fined after he activated a siren while drunk during a party night, causing a huge commotion.