SmogRank / South Korea / Gyeongsangbuk-do / Yecheon
Yecheon, month by month
Yecheon has a measured daily mean on 906 days since 23 March 2024. Its worst month was March 2025, at 101 US AQI (35.6 µg/m³), 214th of 2,862 cities on that month's world ranking. Its cleanest was October 2025, at 36 US AQI (6.5 µg/m³). 2025 averaged 65 US AQI (16.4 µg/m³), against 59 US AQI (13.6 µg/m³) in 2024.
Every month since 2024
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Months without a mean, and why
1 month
| Month | Why |
|---|---|
| Mar 2024 | 7 of 31 days measured; a month needs 22. The others: 2 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Yecheon's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| March 2025 | 10135.6 µg/m³ | 214thof 2,862 | Japan and South Korea, March 2025 |
| March 2026 | 7924.3 µg/m³ | 454thof 2,971 | Japan and South Korea, March 2026 South Korea, 9 to 12 March 2026 |
| February 2026 | 7421.5 µg/m³ | 497thof 2,866 | South Korea and Japan, 10 to 15 February 2026 South Korea, February 2026 |
| April 2024 | 7321.1 µg/m³ | 201stof 2,520 | Japan and South Korea, April 2024 |
| January 2025 | 7320.9 µg/m³ | 267thof 2,474 | Japan and South Korea, 17 to 24 January 2025 South Korea, 13 to 14 January 2025and 1 more |
| November 2025 | 6717.8 µg/m³ | 475thof 2,715 | South Korea and Japan, November 2025 |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Yecheon's worst days
| Day | US AQI | Episode |
|---|---|---|
| 26 Mar 2025 | 489320.0 µg/m³ | Japan and South Korea, March 2025 |
| 27 Mar 2025 | 263188.0 µg/m³ | Japan and South Korea, March 2025 |
| 25 Mar 2026 | 15256.5 µg/m³ | Japan and South Korea, March 2026 |
| 21 Jan 2025 | 14453.0 µg/m³ | Japan and South Korea, 17 to 24 January 2025 |
| 22 Jan 2025 | 14453.0 µg/m³ | Japan and South Korea, 17 to 24 January 2025 |
| 17 Apr 2024 | 14252.3 µg/m³ | Japan and South Korea, April 2024 |
| 24 Mar 2026 | 14051.4 µg/m³ | Japan and South Korea, March 2026 |
| 14 Feb 2026 | 13950.8 µg/m³ | South Korea and Japan, 10 to 15 February 2026 |
| 16 Jan 2026 | 13649.9 µg/m³ | South Korea and Japan, January 2026 |
| 13 Feb 2026 | 13449.1 µg/m³ | South Korea and Japan, 10 to 15 February 2026 |
Daily means, the highest since 23 Mar 2024; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Yecheon, South Korea, 23 Mar 2024 – 12 Oct 2026. Monitor data from Korea Air Ministry of Environment via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/kr/yecheon/history (accessed 12 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Yecheon now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 19:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).