Nationwide warning day for the population on March 12, 2026

The warning day is intended to raise awareness of the topic of warning among all citizens throughout the country and to train citizens in how to behave in an emergency.

There are many disaster scenarios that can be warned against. Warnings can be issued for: Natural hazards (e.g. floods, earthquakes, solar storms), dangerous weather conditions (e.g. thunderstorms, heat, high UV rays), armed violence and attacks, accidents in chemical plants, traffic disruptions, power outages, supply failures (e.g. electricity and water), pathogens, radioactivity or fire.

As there is no standardized warning structure in Hesse, each municipality can set up its own structure and decide how best to warn citizens. In Offenbach, warnings can be issued via sirens.

The city also provides information about hazardous situations via the website - where citizens can see exactly what is happening - social media, radio, notices, in person directly on site, via city information systems and warning apps.

On the warning day, only the state will issue warnings nationwide via the so-called Modular Warning System (MoWaS) using warning apps, radio (only FFH and HR), city information systems and smartphones (cell broadcast).

The Hessian Ministry of the Interior is in charge and the fire department of the city of Offenbach is coordinating the warning day at municipal level.

To receive the test warning on the warning day, you must activate the option to receive "Test warnings" in the device settings (e.g. under "Notifications"). Triggering emergency warnings in a real danger situation, on the other hand, is usually already preset.

The latest update should always be installed so that you can receive warnings on the warning day and in real life. In general, a good internet connection (mobile data/WLAN) must be ensured. Certain system settings are required for both iOS and Android operating systems in order to receive protection warnings. There are also other individual settings that vary depending on the manufacturer and operating system. All operators of the warning apps offer contact options in case of questions or problems.
Please note the following information:

Switch off standby/background update: The smartphone and the warning app must not be in standby (Android) or the background updates (iPhone) switched off. You can switch off the standby mode for the warning app in the settings or switch on / not restrict the background update for the warning app.

Switch on mobile data: If you are on the move, mobile data must be switched on so that you can receive the warning. With Android, you must generally allow the use of mobile data; with iPhone, you can allow the use of mobile data for certain apps.

Sound on: The sound must be switched on in your smartphone.

Do not swap out app: iPhone has the "Swap out app" function. Apps that are not used for a longer period of time are removed from the device. You can deactivate the function in Settings/App Store.

Switch off the do not disturb function: If the do not disturb function is active, you cannot receive any warning messages. You can find the function in Android under Settings/Notifications. If you want to activate it, you can set up exceptions for certain apps. On iPhones, you can find the function under Settings/Focus and can exclude warning apps via Exceptions.

Activate notifications: You can set this up individually for each app for Android under Settings/Apps. For iPhones, activate the notifications for the respective app under Settings/Messages.

Alert app settings: Subscribe to all areas and locations for which you would like to be warned. For example, your place of residence, place of work or education and perhaps even your current location (permission must be granted for the location in the app and smartphone settings). Select the right warning level for you: If you select from the lowest alert level, you will receive all notifications.

Not all cell phones and smartphones can receive cell broadcast messages. Older devices may not be able to receive cell broadcast messages at all.
An operating system update for Android (Google) from version 11 or iOS (Apple) from version 16.1 must be installed.
The cell phone or smartphone must be switched on and must not be in flight mode.

The primary aim of the nationwide warning day is to raise public awareness of the issue of danger. If a warning is received in any form, citizens should inform themselves independently about the situation (switch on the TV and radio) and get an overview of the possible emergency situation.

The city has had a functioning siren network since the beginning of 2025.

The new sirens are considered more crisis-proof than the classic motorized sirens that were used in Offenbach until the 1990s. The new sirens have a rechargeable battery and can continue to function for a set period of time even in the event of power failures or disruptions to the radio network. The sound can be directed in a targeted manner and is louder than the motorized sirens. They can also be triggered digitally.