SmogRank / Japan / Fukuoka / Ōmuta

Ōmuta, month by month

Ōmuta has a measured daily mean on 1,148 days since 28 July 2023. Its worst month was April 2024, at 64 US AQI (15.9 µg/m³), 364th of 2,520 cities on that month's world ranking. Its cleanest was July 2024, at 33 US AQI (6.0 µg/m³). 2025 averaged 56 US AQI (12.0 µg/m³), against 56 US AQI (11.7 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)157 days measured
Each square is a month's mean PM2.5 in US AQI from Ōmuta's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Ōmuta marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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

1 month
MonthWhy
Jul 20234 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.

Ōmuta's worst months

MonthUS AQIDays measuredWorld rankEpisode
April 2024 6415.9 µg/m³30 of 30364thof 2,520Japan and South Korea, April 2024
May 2024 6114.6 µg/m³31 of 31298thof 2,684South Korea and Japan, May 2024
March 2026 6114.5 µg/m³31 of 31894thof 2,971Japan and South Korea, March 2026
January 2025 6114.4 µg/m³31 of 31523rdof 2,474Japan and South Korea, 17 to 24 January 2025
November 2025 6114.4 µg/m³25 of 30612thof 2,715–
September 2024 6114.2 µg/m³24 of 30187thof 2,010Japan and South Korea, September 2024

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.

Ōmuta's worst days

DayUS AQIEpisode
19 Apr 2024 12545.3 µg/m³Japan and South Korea, April 2024
18 Apr 2024 10938.8 µg/m³Japan and South Korea, April 2024
2 Jul 2025 10838.3 µg/m³Japan and South Korea, June and July 2025
1 Jul 2025 10737.9 µg/m³Japan and South Korea, June and July 2025
11 Feb 2024 10336.4 µg/m³Japan, 11 to 12 February 2024
28 Mar 2026 9934.6 µg/m³Japan and South Korea, March 2026
22 Jan 2025 9834.2 µg/m³Japan and South Korea, 17 to 24 January 2025
21 Jan 2025 9633.4 µg/m³Japan and South Korea, 17 to 24 January 2025
3 Jul 2025 9532.8 µg/m³Japan and South Korea, June and July 2025
29 Mar 2026 9432.3 µg/m³Japan and South Korea, March 2026

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, Ōmuta, 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/omuta/history (accessed 12 Oct 2026).

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Ōmuta now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 18:07 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).