SmogRank / Japan / Fukuoka / Wakasugi

Wakasugi, month by month

Wakasugi has a measured daily mean on 1,103 days since 28 July 2023. Its worst month was April 2024, at 57 US AQI (12.2 µg/m³), 689th of 2,520 cities on that month's world ranking. Its cleanest was July 2024, at 31 US AQI (5.6 µg/m³). 2025 averaged 51 US AQI (9.2 µg/m³), against 47 US AQI (8.5 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)118 days measured
JanFebMarAprMayJunJul4 daysAug51#762Sep20 daysOct44#764Nov52#668Dec52#850
Each square is a month's mean PM2.5 in US AQI from Wakasugi'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 Wakasugi 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

2 months
MonthWhy
Sep 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
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.

Wakasugi's worst months

MonthUS AQIDays measuredWorld rankEpisode
April 2024 5712.2 µg/m³30 of 30689thof 2,520Japan and South Korea, April 2024
July 2025 5611.7 µg/m³31 of 31894thof 2,889Japan and South Korea, June and July 2025
March 2025 5410.8 µg/m³29 of 311,461stof 2,862–
March 2026 5410.8 µg/m³29 of 311,464thof 2,971Japan and South Korea, March 2026
August 2026 5410.7 µg/m³31 of 31755thof 2,896–
May 2024 5410.6 µg/m³30 of 31664thof 2,684–

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.

Wakasugi's worst days

DayUS AQIEpisode
19 Apr 2024 12143.5 µg/m³Japan and South Korea, April 2024
11 Feb 2024 9934.8 µg/m³Japan, 11 to 12 February 2024
2 Jul 2025 9030.0 µg/m³Japan and South Korea, June and July 2025
18 Apr 2024 8929.4 µg/m³Japan and South Korea, April 2024
10 Jul 2025 8728.5 µg/m³Japan and South Korea, June and July 2025
3 Jul 2025 8527.5 µg/m³Japan and South Korea, June and July 2025
22 Jan 2025 8527.2 µg/m³Japan and South Korea, 17 to 24 January 2025
28 Mar 2026 8426.7 µg/m³Japan and South Korea, March 2026
21 Jan 2025 8326.5 µg/m³Japan and South Korea, 17 to 24 January 2025
24 Jan 2025 8326.2 µg/m³Japan and South Korea, 17 to 24 January 2025

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, Wakasugi, 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/wakasugi/history (accessed 12 Oct 2026).

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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.

Wakasugi 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).