Norway has a nationwide public warning system that uses sirens to warn the population of imminent danger. The sirens are tested twice a year. This is what the different signals mean.
When the sirens sound three times in a series with a one minute interval between the series, this means “important message – listen to the radio”. If you hear this signal, you should seek information. Information about what is happening and what you should do will be provided through various media, such as radio, television and social media. This signal can be used in both peacetime and wartime.
If the sirens sound an intermittent signal for about one minute, it means “risk of attack – seek shelter”. This signal can be used if there is a risk of an air strike or in war preparedness drills.
When the sirens sound continuously for half a minute, it means the danger is over.
In peacetime, the alarms are tested twice a year, in winter and summer, at 12 noon on the second Wednesday in January and June. The “important message – listen to the radio” signal is used in the tests.
Sometimes the sirens can go off because of a fault. If this happens, you should notify your local Civil Defence unit immediately. You can find a list of all the Civil Defence districts in Norway on the Norwegian Defence's website.
The public warning system can be used in both peacetime and wartime to warn the population of imminent danger. In peacetime, the police are responsible for deciding when to use the alarms. Examples of peacetime emergencies when the alarm might be sounded are an industrial gas leak or a water reservoir dam breach. In wartime, the Norwegian Civil Defence can sound the alarm when there is a risk of an air strike.
There are around 1250 warning systems in Norway. Most of them are in towns and cities. The signals are designed to be heard by more than half the population.