Overview
- A nationwide probe alarm will run on Thursday, 10 September 2026 with a Probewarnung sent at 11:00 and an Entwarnung at 11:45 through the federal Modulares Warnsystem (MoWaS).
- The test will push warnings over multiple channels including Cell Broadcast, the NINA and KATWARN apps, radio, TV, digital city displays and local sirens to check end‑to‑end delivery.
- For the first time Entwarnung (all‑clear) messages can be sent via Cell Broadcast after a November 2025 update, allowing both warning and all‑clear to reach compatible phones directly.
- Participation by municipalities is voluntary so coverage is uneven; reported siren counts include Hamburg 205, Mecklenburg‑Vorpommern about 1,700, Schleswig‑Holstein about 2,800, Hesse about 4,074 and Bavaria more than 11,000, and states are funding targeted upgrades.
- Officials warn many people may not get Cell Broadcast messages if their phones are switched off, in flight mode, lack OS updates (rough guideline Android 11 or iOS 16.1 and later), or are outside network coverage, and the BBK will run a public feedback survey from 11 to 17 September to collect results and guide fixes.