Short answer. South Korea has five civil defence alerts: caution, air raid, CBR, nuclear and all-clear 1. Only the air-raid and nuclear alerts use a siren, sounded for 1 minute together with a voice broadcast; the other three are voice broadcasts only 1. Phones receive cell-broadcast disaster texts in three tiers, and the MOIS Safety Stepping Stone app relays them 45.
Who issues civil defence alerts?
Alerts are issued by the Ministry of the Interior and Safety (MOIS) for the whole country, by provincial governors and city, county and district heads, and, in border areas, by town, township and neighbourhood heads 1. They are broadcast by siren, radio and TV 1. The legal basis is the Civil Defense Act art. 33 and its Enforcement Decree art. 55 23.
What are the five civil defence alerts?
| Alert | Meaning | How it sounds |
|---|---|---|
| 경계경보 (Caution alert) | Attack by enemy aircraft, missiles, land or sea forces is expected | Voice broadcast only, through radio and siren equipment 1 |
| 공습경보 (Air-raid alert) | Attack is imminent or under way | Siren for 1 minute + voice broadcast 1 |
| 화생방경보 (CBR alert) | Chemical, biological or radiological agents released or detected, or contamination expected | Voice broadcast only 1 |
| 핵경보 (Nuclear alert) | Nuclear attack imminent or under way | Siren for 1 minute + voice broadcast 1 |
| 경보해제 (All clear) | Signs of attack have ended or no further attack expected | Voice broadcast only 1 |
When you hear an air-raid or nuclear alert, go to the nearest shelter or underground space; see public shelters. After a nuclear alert, the 7-10 rule on fallout explains why staying sheltered matters.
Are there other siren tones?
Yes. According to the MOIS table, sirens for disaster warnings (not air raids) use a wavering tone: 12 seconds, rising for 2 seconds and falling for 2 seconds, repeated 3 times 1. Other siren uses outside civil defence emergencies use a steady tone for 1 minute 1.
A note on older guides. Some local-government pages still describe the old system: Geumcheon-gu's guide, for example, gives the caution alert as a 1-minute steady tone and the air-raid alert as a 3-minute wavering tone 6. The MOIS page is the current reference 1.
What are the three tiers of disaster texts?
Under MOIS Directive no. 361 (4 February 2026) 4:
| Tier | Used for | Can I turn it off? | Sound |
|---|---|---|---|
| 위급재난문자 (Emergency alert) | Large-scale disaster with feared loss of life, where everyone must receive the message | No | Phone maximum volume, at least 40 dB |
| 긴급재난문자 (Urgent disaster text) | Terrorism, expected radioactive release, evacuation orders, heavy rain, severe flood information, landslide warnings | Yes | Phone maximum volume, at least 40 dB |
| 안전안내문자 (Safety guidance text) | Advisory pre-evacuation, lifting of evacuation orders, other warnings and advisories | Yes | Normal text notification |
Civil-defence (air-raid) alert texts were removed from this directive in 2025 and are governed by the separate civil defence alert rules 4. Keep the urgent tier switched on: it covers radioactive releases and evacuation orders 4.
Which apps relay alerts?
- 안전디딤돌 (Safety Stepping Stone), from MOIS: disaster texts, action guides, shelters, hospitals and pharmacies 5.
- Emergency Ready App, from MOIS: the same information for foreigners in English, Chinese and Japanese; disaster texts are also available in Vietnamese and Thai 5.
A battery radio is on the official kit list; our emergency radio guide explains why it matters when networks fail.
Frequently asked questions
What does a 1-minute siren mean in South Korea?
In a civil defence context, a 1-minute siren with a voice broadcast means an air-raid or nuclear alert: attack imminent or under way 1.
Is there a siren for the all-clear?
No. The all-clear is a voice broadcast only 1.
Can I turn off emergency texts on my phone?
The top tier (위급재난문자) cannot be turned off; the urgent and safety guidance tiers can 4.
Is there an alert app in English?
Yes, the MOIS Emergency Ready App, in English, Chinese and Japanese 5.
Sources
- 행정안전부 (Ministry of the Interior and Safety) — 민방위 제도 운영 — https://mois.go.kr/frt/sub/a06/b12/civildefensework/screen.do (accessed 2026-10-20)
- 국가법령정보센터 (Ministry of Government Legislation) — 민방위기본법 — https://www.law.go.kr/법령/민방위기본법 (accessed 2026-10-20)
- 국가법령정보센터 (Ministry of Government Legislation) — 민방위기본법 시행령 (시행 2026-01-02) — https://www.law.go.kr/법령/민방위기본법시행령 (accessed 2026-10-20)
- 행정안전부, via 국가법령정보센터 — 재난문자방송 기준 및 운영규정 (행정안전부예규 제361호, 2026-02-04) — https://www.law.go.kr/행정규칙/재난문자방송기준및운영규정 (accessed 2026-10-20)
- 행정안전부 (Ministry of the Interior and Safety) — 안전디딤돌 — https://mois.go.kr/frt/sub/a06/b11/safetyStep/screen.do (accessed 2026-10-20)
- 금천구청 (Geumcheon-gu Office, Seoul) — 전시국민행동요령 — https://www.geumcheon.go.kr/portal/contents.do?key=580 (accessed 2026-10-20)
Turn this into action
Your plan for South Korea, 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
- 행정안전부 (Ministry of the Interior and Safety) · 민방위 제도 운영 checked 2026-10-20
- 국가법령정보센터 (Ministry of Government Legislation) · 민방위기본법 checked 2026-10-20
- 국가법령정보센터 (Ministry of Government Legislation) · 민방위기본법 시행령 (시행 2026-01-02) checked 2026-10-20
- 행정안전부, via 국가법령정보센터 · 재난문자방송 기준 및 운영규정 (행정안전부예규 제361호, 2026-02-04) checked 2026-10-20
- 행정안전부 (Ministry of the Interior and Safety) · 안전디딤돌 checked 2026-10-20
- 금천구청 (Geumcheon-gu Office, Seoul) · 전시국민행동요령 checked 2026-10-20