SmogRank / Japan / Oita / Kunisaki

Kunisaki, month by month

Kunisaki has a measured daily mean on 712 days since 28 July 2023. Its worst month was March 2025, at 55 US AQI (11.1 µg/m³), 1,393rd of 2,862 cities on that month's world ranking. Its cleanest was June 2024, at 43 US AQI (7.7 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)136 days measured
Jan8 daysFeb17 daysMar18 daysApr16 daysMay52#860Jun13 daysJul17 daysAug12 daysSep7 daysOct5 days
2025too few days for a mean (a year needs 256)231 days measured
Jan21 daysFeb17 daysMar55#1,393Apr52#1,229May52#914Jun53#1,179Jul18 daysAug52#1,278Sep18 daysOct11 daysNov14 daysDec9 days
2024too few days for a mean (a year needs 257)241 days measured
Jan16 daysFeb9 daysMar47#690Apr54#907May49#1,054Jun43#1,431Jul43#1,423Aug52#682Sep20 daysOct14 daysNov13 daysDec16 days
2023too few days for a mean (a year needs 256)104 days measured
JanFebMarAprMayJunJul2 daysAug19 daysSep48#899Oct21 daysNov20 daysDec20 days
Each square is a month's mean PM2.5 in US AQI from Kunisaki'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 Kunisaki marked; each year, the year's.
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

27 months
MonthWhy
Oct 20265 of 12 days measured; a month needs 9. The others: 7 with readings for part of the day (a day needs 18 hours).
Sep 20267 of 30 days measured; a month needs 21. The others: 23 with readings for part of the day (a day needs 18 hours).
Aug 202612 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jul 202617 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Jun 202613 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
Apr 202616 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Mar 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 202617 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jan 20268 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks.
Dec 20259 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Nov 202514 of 30 days measured; a month needs 21. The others: 16 with under 18 hours of readings or readings that failed our checks.
Oct 202511 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Sep 202518 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jul 202518 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 202517 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jan 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Dec 202416 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Nov 202413 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
Oct 202414 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Sep 202420 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Feb 20249 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 19 with under 18 hours of readings or readings that failed our checks.
Jan 202416 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Dec 202320 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Nov 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Oct 202321 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Aug 202319 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jul 20232 of 31 days measured; a month needs 22. The others: 2 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Kunisaki's worst months

MonthUS AQIDays measuredWorld rankEpisode
March 2025 5511.1 µg/m³24 of 311,393rdof 2,862–
April 2024 5410.8 µg/m³27 of 30907thof 2,520Japan and South Korea, April 2024
June 2025 5310.4 µg/m³24 of 301,179thof 2,508Japan and South Korea, June and July 2025
April 2025 529.8 µg/m³24 of 301,229thof 2,951–
May 2025 529.8 µg/m³25 of 31914thof 2,826–
August 2025 529.8 µg/m³26 of 311,278thof 2,901–

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.

Kunisaki's worst days

DayUS AQIEpisode
3 Jul 2025 10035.3 µg/m³Japan and South Korea, June and July 2025
4 Jul 2025 9734.0 µg/m³Japan and South Korea, June and July 2025
18 Apr 2024 8326.1 µg/m³Japan and South Korea, April 2024
19 Apr 2024 8125.4 µg/m³Japan and South Korea, April 2024
5 Jul 2025 7923.9 µg/m³Japan and South Korea, June and July 2025
11 Feb 2024 7723.3 µg/m³–
10 Jul 2025 7722.9 µg/m³Japan and South Korea, June and July 2025
27 Feb 2025 7220.5 µg/m³–
22 Jan 2025 7120.1 µg/m³–
19 Oct 2023 7119.9 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, Kunisaki, 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/kunisaki/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.

Kunisaki 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).