Germany to test sirens, mobile alerts, and broadcast channels in nationwide warning day

Nationwide alert test procedure

Federal, state, and municipal authorities across Germany will conduct the annual nationwide warning day on 10 September 2026. The test will begin at 11:00, when the Federal Office of Civil Protection and Disaster Assistance dispatches a test warning text through the federal Modular Warning System (MoWaS). This central alert will reach broadcast stations, app servers, and telecommunications networks, which then relay warnings to television screens, radios, and smartphones via Cell Broadcast and warning applications like Nina and Katwarn. Municipalities will trigger local sirens, loudspeaker vehicles, and municipal information boards. An official all-clear signal will follow at 11:45 across the same alert channels.

Regional siren deployments and upgrades

Bremen Senator for the Interior Eva Högl noted the importance of technical readiness ahead of the test.

A warning can bring decisive minutes in an emergency. Therefore, the technical systems must work reliably.

In Bremen, 43 fixed sirens and six mobile sirens are ready for operation. In Lower Saxony, where the federal and state governments funded more than 1,500 sirens over the past five years, authorities do not centrally record total siren counts following Cold War decommissioning. Mecklenburg-Western Pomerania currently operates around 1,700 sirens across its territory, with Interior Minister Christian Pegel pointing to ongoing infrastructure investments.

The past warning days have shown that warning options are continuously expanded and further developed. We will consistently continue along this path, as an efficient and tested warning infrastructure is a central component of effective civil protection.

Digital channels and municipal preparations

In Hamburg, spokeswoman for the interior authority Kim-Katrin Hensmann confirmed the city operates 205 operational sirens, including roughly 120 in storm surge areas and over 80 newly constructed units.

With that, we have really good coverage.

Hamburg will start testing early at 10:45 with an alert sent through warning apps and approximately 1,700 digital urban information displays, where around 300,000 residents already use the Nina app. Traditional gun salutes in the port of Hamburg will no longer serve as a warning method. In North Rhine-Westphalia, Düsseldorf will sound 99 sirens alongside public transport stop displays run by Rheinbahn, following a previous state-level warning day held on 12 March 2026. In Potsdam, all 36 sirens will emit a one-minute continuous tone while local firefighters host an informational stand at the central railway station.

Framework and testing history

The warning day follows a resolution by the Conference of Interior Ministers, taking place annually on the second Thursday in September after its inception on 10 September 2020. Participation for individual municipalities remains voluntary, meaning local siren coverage will vary in states like Bavaria, which counts over 11,000 sirens. The initial test in 2020 saw the Federal Ministry of the Interior label the exercise unsuccessful due to silent sirens and delayed app notifications. Following the test on Thursday, the BBK will gather feedback through an online public survey to evaluate technical performance and transmission speeds.