SmogRank / Japan / Iwate / Ichinoseki

Ichinoseki, month by month

Ichinoseki has a measured daily mean on 1,151 days since 28 July 2023. Its worst month was July 2025, at 55 US AQI (11.3 µg/m³), 993rd of 2,889 cities on that month's world ranking. Its cleanest was January 2026, at 22 US AQI (3.9 µg/m³). 2025 averaged 41 US AQI (7.4 µg/m³), against 39 US AQI (7.1 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)151 days measured
Each square is a month's mean PM2.5 in US AQI from Ichinoseki'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 Ichinoseki 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.

Ichinoseki's worst months

MonthUS AQIDays measuredWorld rankEpisode
July 2025 5511.3 µg/m³31 of 31993rdof 2,889–
April 2024 5310.0 µg/m³30 of 301,023rdof 2,520Japan and South Korea, April 2024
July 2024 529.7 µg/m³31 of 31804thof 2,566Japan, 12 to 14 July 2024
March 2026 529.6 µg/m³31 of 311,755thof 2,971–
June 2024 498.9 µg/m³30 of 30973rdof 2,563–
June 2025 498.9 µg/m³30 of 301,627thof 2,508–

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.

Ichinoseki's worst days

DayUS AQIEpisode
18 Apr 2024 9130.8 µg/m³Japan and South Korea, April 2024
13 Jul 2024 9030.2 µg/m³Japan, 12 to 14 July 2024
16 Jul 2024 7521.9 µg/m³–
24 Mar 2026 7421.7 µg/m³–
9 Jul 2025 7421.2 µg/m³–
26 Apr 2025 7320.7 µg/m³–
25 Mar 2026 7220.5 µg/m³–
25 Mar 2025 7019.2 µg/m³–
14 Jul 2024 7019.1 µg/m³Japan, 12 to 14 July 2024
3 Nov 2023 6919.0 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, Ichinoseki, 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/ichinoseki/history (accessed 12 Oct 2026).

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

Updated 2026-10-12 20:07 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).