SmogRank / Episodes / South Korea
South Korea and Japan, February 2026
For 3 days, from 19 to 21 February 2026, 51 cities in South Korea and Japan had PM2.5 at least twice their usual for the time of year. The worst reading was Yeongju, Gyeongsangbuk-do, South Korea: 47.8 µg/m³ on 21 February, about 2.2× its usual 22.0.
Day by day
How it spread
Every city it reached
| City | Days | Highest | Above usual |
|---|---|---|---|
| ShimonosekiYamaguchi, Japan | 1 | 26.921 February | 3.1× |
| OnomichiHiroshima, Japan | 1 | 29.722 February | 3.1× |
| SaijōEhime, Japan | 1 | 30.023 February | 2.9× |
| ImabariEhime, Japan | 1 | 26.621 February | 2.9× |
| SokchoGangwon-do, South Korea | 2 | 33.321 February | 2.8× |
| FukuokaFukuoka, Japan | 1 | 27.120 February | 2.8× |
| KosongGangwon-do, South Korea | 2 | 28.720 February | 2.8× |
| KasaokaOkayama, Japan | 1 | 25.221 February | 2.8× |
| OnodaYamaguchi, Japan | 2 | 27.921 February | 2.7× |
| FukuyamaHiroshima, Japan | 1 | 27.922 February | 2.7× |
| TakanabeMiyazaki, Japan | 1 | 25.519 February | 2.6× |
| HyūgaMiyazaki, Japan | 1 | 25.919 February | 2.6× |
| SeogwipoJeju-do, South Korea | 1 | 29.420 February | 2.6× |
| HadongGyeongsangnam-do, South Korea | 1 | 36.621 February | 2.5× |
| Jeju CityJeju-do, South Korea | 1 | 30.220 February | 2.4× |
| ChinjuGyeongsangnam-do, South Korea | 1 | 37.321 February | 2.4× |
| Hongch’ŏnGangwon-do, South Korea | 1 | 45.021 February | 2.4× |
| Maebaru-chūōFukuoka, Japan | 2 | 25.820 February | 2.3× |
| GaigeturiJeju-do, South Korea | 1 | 28.520 February | 2.3× |
| HitaOita, Japan | 1 | 32.919 February | 2.3× |
| YeosuJeollanam-do, South Korea | 1 | 29.321 February | 2.3× |
| Tanushimarumachi-toyokiFukuoka, Japan | 1 | 25.020 February | 2.3× |
| ChangwonGyeongsangnam-do, South Korea | 1 | 30.221 February | 2.3× |
| GwangyangJeollanam-do, South Korea | 1 | 29.021 February | 2.3× |
| JumunjinGangwon-do, South Korea | 1 | 28.921 February | 2.3× |
| HayangGyeongsangbuk-do, South Korea | 1 | 35.821 February | 2.3× |
| KwangyangJeollanam-do, South Korea | 1 | 30.021 February | 2.2× |
| SuncheonJeollanam-do, South Korea | 1 | 28.421 February | 2.2× |
| EisenGyeongsangbuk-do, South Korea | 1 | 29.921 February | 2.2× |
| YeongjuGyeongsangbuk-do, South Korea | 1 | 47.821 February | 2.2× |
| TongyeongGyeongsangnam-do, South Korea | 1 | 32.921 February | 2.2× |
| GapyeongGyeonggi-do, South Korea | 1 | 38.621 February | 2.1× |
| T’aebaekGangwon-do, South Korea | 1 | 27.521 February | 2.1× |
| HwacheonGangwon-do, South Korea | 1 | 37.121 February | 2.1× |
| YangguGangwon-do, South Korea | 2 | 36.020 February | 2.1× |
| BoseongJeollanam-do, South Korea | 1 | 26.921 February | 2.1× |
| WaegwanGyeongsangbuk-do, South Korea | 1 | 37.821 February | 2.1× |
| SinhyeonGyeongsangnam-do, South Korea | 1 | 32.121 February | 2.1× |
| KimhaeGyeongsangnam-do, South Korea | 1 | 28.921 February | 2.1× |
| UlsanUlsan, South Korea | 1 | 29.821 February | 2.1× |
| HwadoGyeonggi-do, South Korea | 1 | 40.421 February | 2.1× |
| UngsangGyeongsangnam-do, South Korea | 1 | 26.421 February | 2.1× |
| Koch'angJeollabuk-do, South Korea | 1 | 26.321 February | 2.1× |
| BoryeongChungcheongnam-do, South Korea | 1 | 39.720 February | 2.1× |
| GoseongGyeongsangnam-do, South Korea | 1 | 31.021 February | 2.1× |
| GeojeGyeongsangnam-do, South Korea | 1 | 27.021 February | 2.1× |
| HwasunJeollanam-do, South Korea | 1 | 25.721 February | 2.1× |
| DamyangJeollanam-do, South Korea | 1 | 30.221 February | 2.0× |
| HaenamJeollanam-do, South Korea | 1 | 28.920 February | 2.0× |
| BusanBusan, South Korea | 1 | 30.221 February | 2.0× |
| YeojuGyeonggi-do, South Korea | 1 | 43.221 February | 2.0× |
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in South Korea and Japan
Number 28 of 63 episodes in South Korea and Japan since our records began, by cities reached.
- Japan, June and July 2025508
- Japan and South Korea, March 2025454
- Japan and South Korea, March 2026305
- Japan and South Korea, January 2025274
- Japan and South Korea, February and March 2025192
- Japan, July 2026172
- South Korea and Japan, January 2026169
- South Korea and Japan, February 2026147
- South Korea, February 2025132
- Japan, November 2023131
- South Korea, November 2025128
- Japan, August 2025126
- South Korea and Japan, February 202651
Bars: cities reached; colour: the level of the episode's highest daily reading. All 63.
Use this page
SmogRank, South Korea and Japan, February 2026: 51 cities with PM2.5 at twice their usual or more, 19 to 21 February 2026, smogrank.com/episodes/2026-02-south-korea-and-japan-2 (accessed 2 October 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms.
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes. Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.