SmogRank / Japan / Ehime / Shikokuchūō
Shikokuchūō, month by month
Shikokuchūō has a measured daily mean on 1,088 days since 28 July 2023. Its worst month was April 2024, at 71 US AQI (19.6 µg/m³), 243rd of 2,520 cities on that month's world ranking. Its cleanest was September 2026, at 43 US AQI (7.7 µg/m³). 2025 averaged 58 US AQI (12.8 µg/m³), against 57 US AQI (12.3 µg/m³) in 2024.
Every month since 2023
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
3 months
| Month | Why |
|---|---|
| Jan 2024 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 4 of 31 days measured; a month needs 22. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Shikokuchūō's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2024 | 7119.6 µg/m³ | 243rdof 2,520 | Japan and South Korea, April 2024 |
| March 2025 | 6818.0 µg/m³ | 691stof 2,862 | Japan and South Korea, March 2025 Japan, March 2025and 1 more |
| June 2025 | 6516.4 µg/m³ | 352ndof 2,508 | Japan and South Korea, June and July 2025 |
| April 2025 | 6315.6 µg/m³ | 523rdof 2,951 | – |
| February 2024 | 6315.3 µg/m³ | 332ndof 2,486 | Japan, 14 to 15 February 2024 Japan, 11 to 12 February 2024 |
| July 2025 | 6215.1 µg/m³ | 398thof 2,889 | Japan and South Korea, June and July 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.
Shikokuchūō's worst days
| Day | US AQI | Episode |
|---|---|---|
| 2 Mar 2025 | 15560.5 µg/m³ | Japan and South Korea, February and March 2025 |
| 4 Jul 2025 | 14854.4 µg/m³ | Japan and South Korea, June and July 2025 |
| 1 Mar 2025 | 13750.2 µg/m³ | Japan and South Korea, February and March 2025 |
| 3 Jul 2025 | 13750.2 µg/m³ | Japan and South Korea, June and July 2025 |
| 2 Jul 2025 | 12344.5 µg/m³ | Japan and South Korea, June and July 2025 |
| 15 Feb 2024 | 12143.5 µg/m³ | Japan, 14 to 15 February 2024 |
| 19 Apr 2024 | 12043.1 µg/m³ | Japan and South Korea, April 2024 |
| 5 Jul 2025 | 11240.0 µg/m³ | Japan and South Korea, June and July 2025 |
| 18 Apr 2024 | 11239.8 µg/m³ | Japan and South Korea, April 2024 |
| 27 Apr 2024 | 10637.5 µg/m³ | – |
Daily means, the highest since 28 Jul 2023; 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, Shikokuchūō, Japan, 28 Jul 2023 – 12 Oct 2026. Monitor data from Ministry of the Environment Air Pollutant Wide Area Monitoring System via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/jp/shikokuchuo/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.
Shikokuchūō now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).