Short answer. France alerts the public with sirens of the national alert network, tested on the first Wednesday of each month, and with FR-Alert phone notifications, nationwide since June 2022 and requiring no app or registration 12. The siren alert signal is three cycles of 1 minute 41 seconds separated by 5-second silences; the all-clear is a continuous 30-second tone 1.
Information verified on 20 October 2026.
What does the French alert siren sound like?
| Signal | Pattern |
|---|---|
| Alert | Three sequences of 1 minute 41 seconds, separated by a 5-second silence 1 |
| End of alert | A continuous signal of 30 seconds 1 |
| Dam ("foghorn") signal | A 2-minute cycle alternating 2 seconds of sound and 3 seconds of pause, for hydraulic structures 1 |
| Monthly test | First Wednesday of every month 1 |
The SGDSN guide puts it this way: "En cas d'alerte elles déclenchent un signal sonore correspondant à trois séquences d'1 minute et 41 secondes, séparées par un silence de 5 secondes. La fin de l'alerte est annoncée par un signal continu de 30 secondes" 1.
How many sirens are there?
The SGDSN guide says France has more than 5,000 sirens 1. FR-Alert says more than 2,000 are linked to software that lets them be triggered remotely 2. The two figures measure different things and are given here as each source states them.
What is FR-Alert?
FR-Alert is the phone alert system of the Ministry of the Interior, live since the end of June 2022 in mainland France and the overseas territories 2. It uses cell broadcast; location-based SMS has been announced for later 2.
- No app, no registration. "La réception de cette notification ne nécessite aucune installation préalable sur votre téléphone" 2: you do not need to install anything.
- Specific sound. The notification plays a specific sound, even when the phone is on silent 2.
- End of alert. The end of the alert is also notified 2.
Official information is at fr-alert.gouv.fr 2.
What should I do when the siren sounds?
Get into a solid building, close doors and windows, and do not leave without instructions from the authorities 1. The France public shelters page explains why sheltering in place is the official instruction, since France has no public shelter network. See also Shelter in place or evacuate after a nuclear emergency?.
Where do I get instructions after an alert?
From radio and TV, and from the official accounts of the government, the prefecture and the town hall (mairie) 12. The SGDSN kit list includes a battery-powered radio with spare batteries for this purpose 1 (kit checklist). No official app is required 2.
Frequently asked questions
When are sirens tested in France?
On the first Wednesday of every month 1.
Do I need an app to get FR-Alert?
No. FR-Alert says no installation is needed on your phone and no registration is required 2.
Will FR-Alert sound if my phone is on silent?
Yes. FR-Alert says the notification plays a specific sound even when the phone is on silent 2.
How do I know the danger is over?
For sirens, a continuous 30-second signal announces the end of the alert 1. FR-Alert also sends a notification at the end of the alert 2.
Sources
- Secrétariat général de la défense et de la sécurité nationale (SGDSN) — Tous responsables. Face aux risques, agissons : bien préparés, bien protégés, tous engagés — https://www.ecologie.gouv.fr/sites/default/files/documents/SGDSN_Guide_Tous%20responsables.pdf (accessed 2026-10-20)
- FR-Alert, Ministère de l'Intérieur — À propos FR-Alert ; Foire aux questions (https://fr-alert.gouv.fr/foire-aux-questions) — https://fr-alert.gouv.fr/propos (accessed 2026-10-20)
Turn this into action
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Sources
- Secrétariat général de la défense et de la sécurité nationale (SGDSN) · Tous responsables. Face aux risques, agissons : bien préparés, bien protégés, tous engagés checked 2026-10-20
- FR-Alert, Ministère de l'Intérieur · À propos FR-Alert ; Foire aux questions (https://fr-alert.gouv.fr/foire-aux-questions) checked 2026-10-20