Once a year, on the second Thursday of September, Germany orchestrates a large-scale, Nationwide Alert Day (Warntag) to test the country’s emergency warning systems. In 2025, this exercise will take place on Thursday, September 11, beginning at 11:00 a.m. Authorities will send out practice alerts across multiple channels and devices, including sirens in towns and cities, and the exercise will conclude at approximately 11:45 a.m. with an all-clear signal issued through most alert channels. Citizens are reminded that this is purely a practice exercise, there is no danger.
Nationwide Alert Day serves as a vital opportunity to test and verify the technical reliability of Germany’s warning infrastructure while also raising public awareness about how emergency alerts are communicated. Residents are encouraged to inform children, family, and friends about the exercise and share information via social media to ensure everyone is prepared and aware.
The day’s primary objective is to test a variety of warning channels and ensure that they function properly. Authorities at the federal, state, and local levels work together to activate alerts and identify any weaknesses that may need to be addressed.
The alerts are delivered through a variety of channels, including:
An all-clear signal will be transmitted at around 11:45 a.m. via most alert systems. Currently, the cell broadcast service does not yet transmit the all-clear signal, though service providers are evaluating the possibility for the future.
The Nationwide Alert Day has two main goals:
Through this coordinated exercise, authorities can review the entire alert process, from the initial activation of a warning to the reception by citizens via radios, television, smartphones, digital signage, and sirens. Any weaknesses discovered during the practice are addressed, helping to strengthen the overall resilience of Germany’s civil protection infrastructure.
Citizens should be familiar with the meaning of different siren signals:
These distinct signals allow residents to quickly recognize the nature of the alert and respond appropriately.
The Nationwide Alert Day is a joint initiative of federal, state, and municipal authorities. At the federal level, the Federal Office of Civil Protection and Disaster Assistance (BBK) is responsible for planning and coordination. The respective state ministries of the interior manage implementation at the regional level, while municipal authorities, typically those responsible for civil protection, oversee local operations.
The warning systems are interconnected through the Modular Warning System (MoWaS), which serves as the central hub for alert dissemination. At 11:00 a.m., a practice alert message is sent from MoWaS to all connected warning multipliers, such as broadcast stations and app servers. These multipliers then forward the alerts to individual channels, ensuring a timely and coordinated distribution of information.
While the Nationwide Alert Day is observed across Germany, participation at the municipal level is voluntary. Not all towns or cities may trigger sirens or local alert channels. Citizens are encouraged to check with their local authorities, such as city halls, fire departments, or municipal civil protection offices, to learn how warnings will be issued in their area.
The choice and availability of alert channels depend on local resources and operational capabilities. This flexible approach allows municipalities to tailor the exercise to their infrastructure while contributing to a nationwide assessment of Germany’s overall readiness.