SmogRank / World / Asia / Japan / Hiroshima
Most polluted cities in Hiroshima, Japan
12 measured cities, this year; 12 above the WHO annual guideline. Worst: Onomichi at 13.4 µg/m³, #643 in the world.
About 3.42K people in these 3 cities breathed unhealthy air on an average day so far this year.
Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.
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
Estimated: cities without a monitor
Hiroshima cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Hatsukaichi | ≈ 7 µg/m³ |
| Fuchū | ≈ 7 µg/m³ |
| Fuchūchō | ≈ 7 µg/m³ |
| Kannabechō-yahiro | ≈ 8 µg/m³ |
| Shōbara | ≈ 6 µg/m³ |
| Aki-takata | ≈ 5 µg/m³ |
| Kaitaichi | ≈ 7 µg/m³ |
| Ōno-hara | ≈ 8 µg/m³ |
| Innoshima | ≈ 8 µg/m³ |
| Etajima | ≈ 7 µg/m³ |
| Kumano | ≈ 7 µg/m³ |
| Kōzan | ≈ 7 µg/m³ |
Bad-air episodes in Hiroshima
- Japan and South Korea, July 202616 to 25 July 2026, 10 days205 cities39 µg/m³peak, Mooka
- Japan and South Korea, March 202623 to 31 March 2026, 9 days322 cities86 µg/m³peak, Pohang
- South Korea and Japan, 19 to 21 February 20263 days52 cities48 µg/m³peak, Yeongju
- South Korea and Japan, 10 to 15 February 20266 days153 cities82 µg/m³peak, Wŏnju
- Japan, 14 to 15 February 20262 days51 cities40 µg/m³peak, Ōdate
- South Korea and Japan, January 202615 to 18 January 2026, 4 days176 cities85 µg/m³peak, Pubal
Times when many cities around here had PM2.5 at twice their usual or more on the same days.
Use this board
SmogRank, most polluted cities in Hiroshima, Japan, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/jp/region/hiroshima?w=year.
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.
Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.