Do not be alarmed when the sirens are tested. Read about what the sirens mean and what you should do when you hear them - in real events
Sounding of sirens
When a major accident or disaster involves an acute danger of injury or property damage, it is possible to warn the Danish population of such risk by means of Denmark’s national electronic siren warning system.
What should you do? (instruction in real events)
At the sound of the sirens, go inside and tune into DR or TV2.
Preferably make sure that all bystanders have understood the warning signal. DR and TV2 will now inform the population of the situation, issuing instructions of what to do. These messages will originate from the police or other authorities.
The signals are illustrated in the picture above.
The sirens produce a special sound to signal to warn of a danger situation. This signal consists of a sound that rises fast and then slows down gradually. This signal is sounded four times in total, lasting 45 seconds.
The siren warning system will also be used when the danger is over. The system will produce another sound to signal the end of the danger. This sound signal is one long uniform tone lasting 45 seconds. When this signal has sounded, you may safely go outside again.
About the siren warning system
The Danish Emergency Management Agency (DEMA) operates and maintains the siren warning system.
The system has a total of 1,078 sirens covering about 80 % of the Danish population. A separate uninterruptible power supply allows the sirens to work in the event of a power failure.
The sirens are fixed to buildings or poles in cities and urban areas with more than 1,000 people. Outside these areas, the police may decide to use mobile sirens.
In the event of a major accident or a disaster, the police may decide to use the sirens. At the same time an emergency message will be broadcasted by the two national TV stations DR and TV2.
The police will start the sirens. They are able to warn the entire population in one operation.
Receive warings on you mobile phone
The siren warning system can also be used in regional or local areas where the police will start the sirens individually and so warn specific areas.
- Download the app "Mobilvarsling" and specify the area of which you want to receive warnings about or read more on mobilvarsling.dk (Danish)
Persons who are hard-at-hearing or hearingimpaired may subscribe to the warning system at DEMA and thus receive text message warnings.
- Subscribe for receivning text message warnings (sms) for the hard-at-hearing or hearingimpaired (Danish)
Since 1994 an annual sounding of the siren warning system has always taken place on the first Wednesday in May at noon. All sirens are tested every night (without sound).