Ibi, month by month
Ibi has a measured daily mean on 1,044 days since 28 July 2023. Its worst month was July 2025, at 55 US AQI (11.5 µg/m³), 942nd of 2,889 cities on that month's world ranking. Its cleanest was February 2024, at 15 US AQI (2.7 µg/m³).
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
5 months
| Month | Why |
|---|---|
| May 2025 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Apr 2025 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Mar 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | No day measured. The others: 28 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.
Ibi's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2025 | 5511.5 µg/m³ | 942ndof 2,889 | Japan and South Korea, June and July 2025 |
| August 2025 | 5410.7 µg/m³ | 1,069thof 2,901 | – |
| June 2025 | 529.7 µg/m³ | 1,391stof 2,508 | Japan and South Korea, June and July 2025 |
| July 2026 | 498.9 µg/m³ | 1,635thof 2,784 | – |
| March 2026 | 488.7 µg/m³ | 1,950thof 2,971 | – |
| February 2026 | 468.3 µg/m³ | 1,883rdof 2,866 | – |
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.
Ibi's worst days
| Day | US AQI | Episode |
|---|---|---|
| 14 Jun 2026 | 15358.0 µg/m³ | – |
| 9 Jul 2025 | 10236.0 µg/m³ | Japan and South Korea, June and July 2025 |
| 1 Jul 2025 | 8728.2 µg/m³ | Japan and South Korea, June and July 2025 |
| 8 Jul 2025 | 8225.9 µg/m³ | Japan and South Korea, June and July 2025 |
| 29 Mar 2026 | 7924.2 µg/m³ | – |
| 5 Jul 2025 | 7823.5 µg/m³ | Japan and South Korea, June and July 2025 |
| 21 May 2025 | 7723.2 µg/m³ | – |
| 10 Jul 2025 | 7723.1 µg/m³ | Japan and South Korea, June and July 2025 |
| 4 Jul 2025 | 7622.7 µg/m³ | Japan and South Korea, June and July 2025 |
| 20 May 2025 | 7522.1 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, Ibi, 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/ibi/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.
Ibi now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 17:07 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).