SmogRank / Seonghwan / Waegwan

Seonghwan vs Waegwan: PM2.5 compared

Over the last year, Seonghwan's air was 37% more polluted than Waegwan's: PM2.5 averaged 23.5 µg/m³ against 17.2, on the 332 days both cities were measured. Seonghwan had the dirtier air on 261 of those days, Waegwan on 70. Seonghwan was over the WHO's daily guideline of 15 µg/m³ on 219 of them, Waegwan on 153.

Right now

Seonghwan#40on the 24-hour board of 2,706, at 110 US AQI (39.1 µg/m³)
Waegwan#291on the 24-hour board of 2,706, at 64 US AQI (15.9 µg/m³)

The last year, day by day

Seonghwan
Waegwan
Each city's daily mean from 10 Oct 2025 to 9 Oct 2026, one stripe a day, coloured by band. A blank stripe is a day without a daily mean.

Month by month

Seonghwan, Nov 2025: 31.9 µg/m³Waegwan, Nov 2025: 21.2 µg/m³Nov2025Seonghwan, Dec 2025: 26.0 µg/m³Waegwan, Dec 2025: 19.5 µg/m³DecSeonghwan, Jan 2026: 24.8 µg/m³Waegwan, Jan 2026: 19.2 µg/m³Jan2026Seonghwan, Feb 2026: 32.0 µg/m³Waegwan, Feb 2026: 25.8 µg/m³FebSeonghwan, Mar 2026: 39.2 µg/m³Waegwan, Mar 2026: 27.9 µg/m³MarSeonghwan, Apr 2026: 26.2 µg/m³Waegwan, Apr 2026: 15.3 µg/m³AprSeonghwan, May 2026: 20.0 µg/m³Waegwan, May 2026: 15.6 µg/m³MaySeonghwan, Jun 2026: 19.0 µg/m³Waegwan, Jun 2026: 13.7 µg/m³JunSeonghwan, Jul 2026: 13.4 µg/m³Waegwan, Jul 2026: 13.7 µg/m³JulSeonghwan, Aug 2026: 15.4 µg/m³Waegwan, Aug 2026: 11.5 µg/m³AugSeonghwan, Sep 2026: 15.6 µg/m³Waegwan, Sep 2026: 11.8 µg/m³SepOct
Monthly means in µg/m³ over the days both cities were measured. Solid: Seonghwan. Faded: Waegwan. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Year by year

YearSeonghwanWaegwanDays both measuredDays Seonghwan was worse
2026 so far7766258199
20257665345284
20247162278205

Means in US AQI over the days both cities were measured that year; a year shows once they share 30 such days.

Each city's worst days

Seonghwan

Waegwan

Daily means in US AQI, with µg/m³ beside them, since the index stops at its top value, over the days both cities were measured in the last year. Each date opens that day's world board.

Compare either city with another

Seonghwan

Side by side with Pyeongtaek (the nearest), Kimje (South Korea's 2nd worst on 30 days), Gujranwala (the world's worst on 30 days).

Waegwan

Side by side with Gumi (the nearest), Gujranwala (the world's worst on 30 days).

Use this page

SmogRank, PM2.5 daily means compared, Seonghwan and Waegwan, 10 Oct 2025 – 9 Oct 2026, smogrank.com/compare/kr-seonghwan/kr-waegwan (accessed 9 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.

The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.

Updated 2026-10-09 15:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published (why we use them).