Korean weather alerts: 주의보, 경보, and the new 폭염중대경보

On 2 August 2026, Yangsan in South Gyeongsang recorded 42.5°C — the highest air temperature in the 122 years since modern observation began in Korea, beating the 41.0°C set in Hongcheon on 1 August 2018 (뉴시스, 서울신문). The next day, parts of Seoul went under a 폭염중대경보; on 4 August the whole city did, for the first time ever (한국경제, The Korea Herald). If you were anywhere in Korea, your phone spent the week buzzing.

Here is the part worth your study time. That alert level did not exist last summer. It is one piece of a vocabulary system that is small, rigid, and almost perfectly regular — and once you own it, you can read a flood alert, a cold-wave alert, or a typhoon alert with the same three words.

The three words that do all the work

Korean hazard alerts come in tiers, and the tier is a separate word bolted onto the hazard.

주의보 (注意報) — advisory. 주의 “caution” + 보 “report”. Conditions are getting bad; pay attention.
경보 (警報) — warning. 경 “warn” + 보. Conditions are dangerous.
중대경보 (重大警報) — serious warning. 중대 “grave, momentous” + 경보. New in 2026, and so far heat only.

Above all three sits the umbrella term 특보 (特報), literally “special report”. 기상특보 is any weather alert, at any tier. When a news anchor says 폭염특보가 발효 중입니다, they are being deliberately non-specific: some level of heat alert is in force somewhere.

The high-leverage piece here is 보 (報), “report, notification”. It is productive, and it shows up everywhere once you notice it: 예보 (豫報) forecast, 일기예보 weather forecast, 속보 (速報) breaking news, 경보, 주의보. You are not memorising four unrelated nouns. You are memorising one suffix and three modifiers.

The pattern is hazard + tier

The Korea Meteorological Administration issues 기상특보 for eleven hazard types, each with tiers (기상특보 발표기준, 기상청):

강풍 strong wind · 풍랑 high seas · 호우 heavy rain · 대설 heavy snow · 건조 dryness · 폭풍해일 storm surge · 태풍 typhoon · 황사 yellow dust · 폭염 extreme heat · 열대야 tropical night · 한파 cold wave

Snap the tier on and you have the word: 호우주의보, 호우경보, 대설주의보, 한파경보, 건조주의보, 태풍경보. That is eleven nouns plus two suffixes, not twenty-two vocabulary items — and the compounds are transparent enough that you can decode one you have never seen.

What actually changed in 2026

In May, the KMA announced the first overhaul of the heat alert system in eighteen years, in force from 1 June (기상청 보도자료, 뉴시스):

Alert	Trigger
폭염주의보	daily max apparent temperature 33°C+, expected to last 2 days or more
폭염경보	daily max apparent temperature 35°C+, expected to last 2 days or more
폭염중대경보	in an area already at 폭염경보 level, daily max apparent temperature 38°C+ or daily max air temperature 39°C+, expected for even a single day
열대야주의보	newly created in 2026 for nights that fail to cool down

The linguistically interesting bit is the phrase that disappeared. The two older tiers both require 2일 이상 지속 — “sustained for two days or more”. The new top tier fires when the threshold is expected 하루만 — “for just one day”. A single Korean adverbial carries the entire policy change: the old system could let the worst day pass before it said anything.

A note on sourcing: reporting differs on whether the 열대야주의보 threshold is a flat 25°C nationwide or varies by region. Treat the exact number as unsettled and check the KMA directly.

The verbs nobody teaches you

Learners reliably learn 폭염경보 and then cannot build a sentence with it, because alerts take a specific and fairly closed set of verbs.

발효되다 (發效) — take effect, be in force. The default verb.
해제되다 (解除) — be lifted.
격상되다 (格上) — be upgraded a tier.
발표하다 (發表) — issue, with the KMA as the subject.

오늘 서울에 폭염경보가 발효됐어요. A heat warning took effect in Seoul today.

폭염주의보가 경보로 격상됐습니다. The heat advisory has been upgraded to a warning.

비 그치고 나서 호우주의보는 해제됐대요. Apparently the heavy-rain advisory was lifted after the rain stopped.

Note the particle work: the alert is the grammatical subject with 이/가, the place takes 에, and the tier you are moving to takes (으)로. Those three patterns cover most sentences you will ever need here. In casual speech people also just say the alert 떴다 — 폭염경보 떴대, “apparently a heat warning is up” — which is fine with friends and wrong in anything written.

체감온도 is the hinge

Look again at the thresholds: they are set in 체감온도, not 기온. 체감온도 (體感溫度) is 체감 “bodily sensation” + 온도 “temperature” — apparent temperature, what the air actually does to a body. Korea moved its heat criteria from air temperature to apparent temperature in 2020, precisely because humidity makes 33°C mean two different things.

That is a gift to a learner, because it means the bureaucratic word and the word you would say out loud are pointing at the same thing. 체감온도가 38도까지 올라간대요 — “they say it’ll feel like 38” — is a sentence you can use in an office and in a text message.

Two more compounds worth cracking open:

폭염 (暴炎) — 폭 “violent” + 염 “blaze”. The same 폭 as in 폭우 violent rain, 폭설 violent snow, 폭풍 violent wind. Another one-character key that unlocks a set.
열대야 (熱帶夜) — 열대 “the tropics” + 야 “night”. The KMA defines it as a night where the minimum temperature between 18:01 and 09:00 the next morning never drops below 25°C.

The ladder from your body to the bulletin

This is the mental model to keep. Korean gives you four rungs for the same August afternoon, and they are not interchangeable.

1. Sensation — what your body reports. 덥다 hot · 습하다 humid · 후텁지근하다 muggy and close · 푹푹 찌다 to be sweltering, literally “to steam”

밖에 잠깐 나갔는데 푹푹 쪄요. I went out for a minute and it’s absolutely sweltering.

2. Everyday description — named kinds of heat. Korean splits these by humidity, and the split is real, not decorative (YTN 뉴스말모이, 가톨릭평화신문 우리말 바른말):

Word	Image	Humidity
무더위	the general term; commonly explained as 물 “water” + 더위 “heat”	high
찜통더위	a food steamer	high
가마솥더위	a cast-iron cauldron	high
불볕더위	blazing sunlight	low — shade actually helps

So 오늘은 습해서 찜통더위예요 and 햇볕이 너무 뜨거워요, 완전 불볕더위네요 describe genuinely different days. Picking the wrong one is the kind of mistake that reads as translated rather than spoken. The dictionary entries are worth reading yourself in the 표준국어대사전.

3. Phenomenon — the technical noun. 폭염, 열대야. Neutral, countable, measurable. You will hear 열대야 일수 “number of tropical nights” on the news; you would not normally complain to a friend in these words, though 어제 열대야 때문에 한숨도 못 잤어 is perfectly natural.

4. Official — the alert. 폭염경보, 열대야주의보. Written and broadcast register.

That ladder — sensation, everyday word, technical phenomenon, official term — is not specific to heat. It is how Korean organises most of its hazard and health vocabulary, and once you have climbed it for one topic you will recognise the shape of the next one.

Reading the text message itself

The alerts reach you as 재난문자. Since 2016 there have been three grades, and knowing which is which tells you how alarmed to be (대한민국 정책브리핑):

안전안내문자 — safety notice. Weather alerts arrive as these. Silenceable.
긴급재난문자 — emergency alert. Situations needing action or evacuation. Loud.
위급재난문자 — critical alert. The top grade. Louder.

The prose style inside them is consistent and worth imitating in any formal Korean writing: bare Sino-Korean nouns, no subject, and -하세요 imperatives stacked in a row. The recurring verbs are 자제하다 “refrain from”, 유의하다 “take care”, and 삼가다 “abstain from” — all of which sound stiff in conversation and exactly right in a notice.

야외 활동을 자제하시고 충분히 수분을 섭취하세요. Refrain from outdoor activity and drink plenty of fluids.

Compare what you would actually say to a friend: 오늘 너무 더우니까 밖에 나가지 마. Same instruction, completely different register. Being able to move between those two lines is most of what “advanced” means.

The recap

주의보 < 경보 < 중대경보, all under 특보. 보 = report.
Hazard + tier. Eleven hazards, two suffixes, decodable compounds.
The verbs are 발효되다 / 해제되다 / 격상되다, with 에 for place and (으)로 for the new tier.
Thresholds are in 체감온도, which is also a word you can say out loud.
Four rungs: 덥다 → 찜통더위 → 폭염 → 폭염경보. Match the rung to the room.

None of this is worth memorising from a list. It is worth meeting in real sentences until it sticks, which is roughly the argument in how I improved my Korean listening — the words you keep are the ones you met somewhere real, at a level you could almost handle. If that sounds like your problem too, up103 gives Founding Learners 6 months free, then 50% off for life, at app.up103.com.

— 에드, up103