Warntag: Germany to test sirens and alerts on September 11

On September 11, 2025, Germany will hold its annual Warning Day (Warntag) to test its emergency alert system. Here’s what you need to know: 

Emergency alert test in Germany on September 11, 2025

At 11am on September 11, 2025, people in Germany should receive an emergency alert on their mobile phone. This is a test emergency alert, and you do not need to do anything. An “all clear” (Entwarnung) alert will follow at 11.45am.

Germany tests its emergency alert system annually in the second week of September. Each year, the federal government tries to increase the number of people the warning message reaches while making sure the message is delivered as promptly as possible.

You should receive the message on your mobile phone, but might also notice it on train platform displays, on the TV, via the radio or NINA and Katwarn warning apps. If you haven't received the message, make sure your mobile phone's operating system is up to date. If your phone receives messages via cell broadcast, you might not receive the “all clear” message.

Sirens in Germany on September 11

You may also hear sirens at 11am on September 11. This depends on where in Germany you are. Regions and communes across the country can choose to test their siren warning systems on a Warntag, but they are not obliged to.

The first warning siren at 11am will be an ascending and descending wailing tone lasting for one minute. The “all clear” tone at 11.45am will be a continuous tone for one minute.

Germany’s Federal Office for Population Protection and Catastrophe Help suggests speaking to vulnerable groups, such as people who have fled war, the elderly and children, before the siren sounds, so that they can expect the alert and know there is nothing to worry about.