SmogRank / Japan / Chiba / Motona

Motona, month by month

Motona has a measured daily mean on 857 days since 2 May 2024. Its worst month was July 2024, at 57 US AQI (12.3 µg/m³), 386th of 2,566 cities on that month's world ranking. Its cleanest was December 2024, at 24 US AQI (4.4 µg/m³).

Every month since 2024

Each square is a month's mean PM2.5 in US AQI from Motona'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 Motona marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Unhealthy for 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

Motona's worst months

MonthUS AQIDays measuredWorld rankEpisode
July 2024 5712.3 µg/m³31 of 31386thof 2,566–
August 2025 5511.0 µg/m³31 of 311,001stof 2,901Japan, 4 to 5 August 2025
July 2026 529.7 µg/m³31 of 311,444thof 2,784–
March 2025 529.6 µg/m³31 of 311,665thof 2,862Japan and South Korea, March 2025
July 2025 529.6 µg/m³29 of 311,361stof 2,889Japan and South Korea, June and July 2025
April 2025 529.5 µg/m³26 of 301,321stof 2,951–

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.

Motona's worst days

DayUS AQIEpisode
7 Jul 2025 11340.5 µg/m³Japan and South Korea, June and July 2025
26 Mar 2025 11039.3 µg/m³Japan and South Korea, March 2025
8 Jul 2025 10235.9 µg/m³Japan and South Korea, June and July 2025
6 Jul 2025 10035.4 µg/m³Japan and South Korea, June and July 2025
4 Aug 2025 8225.6 µg/m³Japan, 4 to 5 August 2025
5 Jul 2024 8024.4 µg/m³–
25 Aug 2025 7823.8 µg/m³–
22 Jul 2024 7521.9 µg/m³–
6 Jul 2024 7421.4 µg/m³–
9 Jul 2025 7421.2 µg/m³Japan and South Korea, June and July 2025

Daily means, the highest since 2 May 2024; 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, Motona, Japan, 2 May 2024 – 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/motona/history (accessed 13 Oct 2026).

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

Updated 2026-10-13 03:07 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).