Short answer. Brazil warns people mainly by phone. Since 1 October 2025, the cell broadcast system Defesa Civil Alerta covers the whole country and reaches compatible 4G and 5G phones with no registration 12. Free SMS alerts are available by texting your postal code (CEP) to 40199 34. There is no national siren code; sirens exist locally around the Angra nuclear plant 6, and dam emergency plans must include a sound alert system 7.
What is Defesa Civil Alerta?
It is Brazil's cell broadcast system: civil defence sends a message to compatible phones in the area at risk, with no registration needed 12. It works on compatible phones connected to 4G and 5G networks 1. Anatel, the telecom regulator, coordinates the alerts with mobile operators 2, and state and municipal civil defence agencies write the content.
The roll-out went region by region 1:
| Region | Start |
|---|---|
| South and Southeast | December 2024 |
| Northeast | June 2025 |
| North | September 2025 |
| Centre-West, and the whole country | 1 October 2025 |
The national page notes that the Centre-West start, on 1 October 2025, was the "same date the tool became available throughout Brazil" 1.
What do the alert levels mean?
| Level | Meaning | Sound |
|---|---|---|
| Extremo (extreme) | Highest level: extreme threat to life or property; take protective action immediately | Siren-like sound, even in silent mode 1 |
| Severo (severe) | Less immediate urgency; more time to protect yourself | SMS-like beep that does not sound in silent mode 1 |
| Demonstração (demonstration) | Test messages sent during the roll-out to introduce the system | — 1 |
An "Extremo" alert is designed to wake you: read it and act at once. A "Severo" alert can arrive silently, so check your phone when you hear of severe weather.
How do you sign up for SMS alerts?
Text the CEP of your home, or of any other place that matters to you, to 40199. The service is free 345. To see which CEPs you have registered, send CONSULTAR to 40199 5. You can register the CEPs of other places that matter to you as well 3.
Which other channels carry alerts?
Civil defence also sends alerts by WhatsApp (save the number (61) 2034-4611 and send "oi") and Telegram 5, and on pay-TV and Google Public Alerts with no registration 2. Keeping a battery-powered radio is part of Paraná's kit list 3; see our guide on emergency radios.
Are there outdoor sirens in Brazil?
Only locally. We found no national siren signal code.
- Angra nuclear plant. Eight high-power omnidirectional electronic sirens (115 dB, 1,600 m range) cover the inhabited area of the 5 km emergency planning zone (ZPE-5) around the plant, at Frade and Mambucaba. They can play a tone and recorded or live voice messages 6. See our Brazil iodine page for the planning zones.
- Dams. Dam emergency action plans must provide "a sound system or another more effective technological solution" for alerts, with a range set by the supervising body, as well as marked escape routes and meeting points (Lei 12.334/2010, as amended by Lei 14.066/2020) 7. If you live downstream of a dam, ask your municipal civil defence about its plan.
For sirens in other countries and what to do when you hear one, see our air raid alert guide.
Frequently asked questions
Do I need to register for Defesa Civil Alerta?
No. Cell broadcast alerts reach compatible 4G and 5G phones in the area automatically 12. SMS alerts via 40199 do require you to send your CEP 3.
Will an alert sound if my phone is on silent?
An "Extremo" alert plays a siren-like sound even in silent mode; a "Severo" alert does not 1.
Is the SMS service free?
Yes. Texting your CEP to 40199 is free 34.
Who decides what an alert says?
State and municipal civil defence agencies; Anatel coordinates delivery with operators 2.
Sources
- Ministério da Integração e do Desenvolvimento Regional (MIDR) – Defesa Civil Nacional — Defesa Civil Alerta — https://www.gov.br/mdr/pt-br/assuntos/protecao-e-defesa-civil/defesa-civil-alerta (accessed 2026-10-20)
- Agência Nacional de Telecomunicações (Anatel) — Alertas de Desastres — https://www.gov.br/anatel/pt-br/dados/utilidade-publica/alertas-de-desastres (accessed 2026-10-20)
- Coordenadoria Estadual da Defesa Civil do Paraná — Kit de Emergência pessoal — https://www.defesacivil.pr.gov.br/Pagina/Kit-de-Emergencia-pessoal (accessed 2026-10-20)
- Defesa Civil do Estado de São Paulo — Plano familiar de emergência - SP Sempre Alerta — https://www.spsemprealerta.sp.gov.br/orientacoes/plano-familiar-de-emergencia/ (accessed 2026-10-20)
- Coordenadoria Estadual da Defesa Civil do Paraná — Coordenadoria Estadual da Defesa Civil do Paraná (alertas: SMS 40199, WhatsApp, Telegram) — https://www.defesacivil.pr.gov.br/ (accessed 2026-10-20)
- Gabinete de Segurança Institucional da Presidência da República (GSI) — Existe algum plano para fazer frente a alguma situação de emergência? — https://www.gov.br/gsi/pt-br/assuntos/apoio/acervo/imagens-acesso-a-informacao/plano-para-fazer-frente-a-alguma-situacao-de-emergencia.pdf (accessed 2026-10-20)
- Presidência da República (Planalto) — Lei nº 12.334, de 20 de setembro de 2010 (Política Nacional de Segurança de Barragens) — https://www.planalto.gov.br/ccivil_03/_ato2007-2010/2010/lei/l12334.htm (accessed 2026-10-20)
Turn this into action
Your plan for Brazil, worked out for your household.
- Water, food and equipment counted for each person and pet
- The nuclear plants and zones around your home
- Phaenyx Safe: one tap to tell your people you are safe
Sources
- Ministério da Integração e do Desenvolvimento Regional (MIDR) – Defesa Civil Nacional · Defesa Civil Alerta checked 2026-10-20
- Agência Nacional de Telecomunicações (Anatel) · Alertas de Desastres checked 2026-10-20
- Coordenadoria Estadual da Defesa Civil do Paraná · Kit de Emergência pessoal checked 2026-10-20
- Defesa Civil do Estado de São Paulo · Plano familiar de emergência - SP Sempre Alerta checked 2026-10-20
- Coordenadoria Estadual da Defesa Civil do Paraná · Coordenadoria Estadual da Defesa Civil do Paraná (alertas: SMS 40199, WhatsApp, Telegram) checked 2026-10-20
- Gabinete de Segurança Institucional da Presidência da República (GSI) · Existe algum plano para fazer frente a alguma situação de emergência? checked 2026-10-20
- Presidência da República (Planalto) · Lei nº 12.334, de 20 de setembro de 2010 (Política Nacional de Segurança de Barragens) checked 2026-10-20