SmogRank / World / Asia / Japan / Hiroshima
Most polluted cities in Hiroshima, Japan
12 measured cities, last 30 days; 0 above the WHO 24-hour guideline. Worst: Onomichi at 9.7 µg/m³, #678 in the world.
About 0 people in these 3 cities breathed unhealthy air on an average day over the last 30 days.
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.
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SmogRank, most polluted cities in Hiroshima, Japan, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/jp/region/hiroshima?w=30d.
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.