Alarms & Sirens in Switzerland

Alarms & Sirens in Switzerland

There are approximately 7.200 alarms in Switzerland, placed throughout the country as part of the Polyalert or flood alarm system, so that the entire population can be alerted and information quickly circulated, should an emergency situation ever arise. It’s a good idea to learn about what these alarms are and what they mean, so you know what to do if you hear one.

Polyalert: A network of alarms all over Switzerland

Polyalert is a network of alarms placed throughout Switzerland, set up by the Swiss government to warn citizens of impending attacks or hazards and inform the emergency services of an imminent need. Of the roughly 7.200 alarms in Switzerland, 5.000 of them are stationary, whilst the remaining are mobile and mostly used in remote areas. All Swiss cities have alarm systems, each with its own unique sound.

After these alarms are sounded to give the initial warning sign, the protocol is for further information to be spread via radio or through the Alertswiss mobile app. However, in some cases, information might be spread using a megaphone, leaflets or couriers. It is important to remain vigilant, but remember that the alarm may be a test.

Testing the alarms in Switzerland

All alarms in Switzerland are tested annually, on the first Wednesday of February. Residents are notified beforehand and no further action needs to be taken. The general alarm is sounded throughout Switzerland from 1.30pm and can continue until 2pm in some places.

The flood alarm is tested from 2.15pm until 3pm at the latest and is usually only tested in areas close to dams.

Types of Swiss alarms

There are two types of alarm in Switzerland:

  • The “general alarm”
  • The “flood alarm”

What to do when the general alarm is sounded

The general alarm is sounded to alert the population to a possible threat, such as a natural disaster or war. The alarm lasts for one minute and is repeated at two-minute intervals. When the general alarm is sounded, you should turn on the radio and wait for more information. You can also visit the Alertswiss website or the mobile app.

What to do in case of a flood alarm

People living below dams in Switzerland are warned by a flood alarm and special sirens, should the risk of flooding ever occur. This warning siren consists of deep, 20-second alarms that repeat every 10 seconds. Anyone who hears the flood alarm should leave the area immediately, follow local guidelines or wait for further instructions.

Alarms on Swiss lakes

To protect the safety of swimmers and boat users, every Swiss lake has a designated alarm system to warn lake users of an impending danger. These systems are usually flashing amber lights that have to be visible on all areas of the lake. A slow rotation of an amber light is used to signify a small danger such as a strong wind, rough conditions or hazards in the water.

A continual flashing amber light indicates a danger related to weather, hazards or flooding. If you are on the water when this light is flashing, it is highly recommended that you get out of the water.

Iodine requirement in Swiss houses

Switzerland currently uses three nuclear power plants to produce electricity. If you live within 50 kilometres of one of these nuclear power plants (which includes major Swiss cities like Zurich, Basel and Aarau), your local council (Gemeinde) will provide every resident with a dose of Iodine to be taken in the event of a nuclear meltdown, signalled by a general alarm and subsequent radio alert. Do not take this medication until instructed to do so by an official source. 

Read also