SmogRank / Japan / Miyagi / Sendai

Sendai, month by month

Sendai has a measured daily mean on 1,153 days since 28 July 2023. Its worst month was July 2025, at 58 US AQI (12.9 µg/m³), 662nd of 2,889 cities on that month's world ranking. Its cleanest was December 2024, at 19 US AQI (3.4 µg/m³). 2025 averaged 41 US AQI (7.3 µg/m³), against 37 US AQI (6.7 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)156 days measured
Each square is a month's mean PM2.5 in US AQI from Sendai'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 Sendai 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.

Sendai's worst months

MonthUS AQIDays measuredWorld rankEpisode
July 2025 5812.9 µg/m³31 of 31662ndof 2,889Japan and South Korea, June and July 2025
April 2024 5511.1 µg/m³30 of 30857thof 2,520Japan and South Korea, April 2024
March 2025 529.5 µg/m³28 of 311,686thof 2,862–
June 2025 529.5 µg/m³30 of 301,450thof 2,508Japan and South Korea, June and July 2025
March 2026 519.2 µg/m³31 of 311,840thof 2,971–
May 2026 509.0 µg/m³31 of 31998thof 2,874–

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.

Sendai's worst days

DayUS AQIEpisode
18 Apr 2024 14553.2 µg/m³Japan and South Korea, April 2024
9 Jul 2025 9130.4 µg/m³Japan and South Korea, June and July 2025
26 Mar 2025 7722.8 µg/m³–
8 Jul 2025 7522.0 µg/m³Japan and South Korea, June and July 2025
24 Mar 2026 7421.6 µg/m³–
13 Jul 2024 7220.3 µg/m³–
19 Apr 2025 7220.2 µg/m³–
16 Jul 2026 7119.7 µg/m³–
30 Jul 2023 7019.3 µg/m³–
7 Jun 2025 7019.3 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, Sendai, 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/sendai/history (accessed 12 Oct 2026).

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

Updated 2026-10-12 17:07 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).