Overview

• At 11:00 the BBK will trigger a nationwide test alert via MoWaS with an all-clear planned around 11:45.
• Multiple channels will carry the test, including sirens, radio and TV, NINA, KATWARN and BIWAPP apps, digital displays, Deutsche Bahn systems, loudspeaker vehicles and Cell Broadcast to phones.
• Reception varies by location because participation is voluntary and siren coverage is uneven, with some cities such as Munich relying on digital alerts in place of fixed sirens.
• Authorities advise using up-to-date phones for Cell Broadcast and checking app settings for push notifications, with some regions noting slight timing offsets due to local dispatch centers.
• An online survey at warntag-umfrage.de runs through September 18 to gather citizen feedback that will guide system improvements.