Denmark’s emergency sirens tested today with dozens out of service

Denmark’s nationwide emergency siren test took place at noon on Wednesday, but 50 of the country’s roughly 1,000 warning sirens remained silent due to technical issues, according to the Danish Emergency Management Agency (Beredskabsstyrelsen).

The annual test, held on the first Wednesday of May, verifies the system’s ability to alert the public in crises such as toxic smoke, fires, or war. However, the agency confirmed that some sirens are always non-operational due to ongoing maintenance.

Bjarne Nigaard, secretary-general of Danske Beredskaber—the association of municipal emergency units—called the outages “very regrettable,” emphasizing the sirens’ role in warning residents near hazards like chemical leaks. “It’s a risk if people don’t receive timely warnings and remain in dangerous areas too long,” he told public broadcaster DR.

Nigaard noted that while sirens are often associated with wartime threats, they are more frequently used for urgent civilian alerts. He questioned why increased national focus on emergency preparedness hasn’t prioritized siren maintenance.

Rasmus Dahlberg, a societal security lecturer at Roskilde University, downplayed concerns, citing modern alternatives like the mobile alert system S!RENEN, which reached 91% of Danish adults last year. “The combination of sirens and digital alerts ensures most people in a crisis zone will be notified,” he said.

Authorities also use emergency broadcasts on national radio and TV channels, alongside mobile alerts, to supplement the siren network. The test included three phases: a 45-second rising-and-falling tone at 12:00 and 12:04, followed by a 45-second steady tone at 12:08 to signal the all-clear.