SmogRank / Japan / Chiba / Narita

Narita, month by month

Narita has a measured daily mean on 1,135 days since 28 July 2023. Its worst month was July 2024, at 59 US AQI (13.3 µg/m³), 274th of 2,566 cities on that month's world ranking. Its cleanest was September 2026, at 29 US AQI (5.3 µg/m³). 2025 averaged 50 US AQI (9.0 µg/m³), against 44 US AQI (7.9 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)147 days measured
Each square is a month's mean PM2.5 in US AQI from Narita'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 Narita 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.

Narita's worst months

MonthUS AQIDays measuredWorld rankEpisode
July 2024 5913.3 µg/m³31 of 31274thof 2,566–
August 2025 5611.9 µg/m³31 of 31789thof 2,901–
July 2025 5410.7 µg/m³31 of 311,116thof 2,889Japan and South Korea, June and July 2025
July 2026 5410.7 µg/m³31 of 311,187thof 2,784–
November 2025 5310.4 µg/m³26 of 30955thof 2,715–
December 2023 5310.2 µg/m³26 of 31658thof 2,247–

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.

Narita's worst days

DayUS AQIEpisode
7 Jul 2025 11039.3 µg/m³Japan and South Korea, June and July 2025
6 Jul 2025 10938.6 µg/m³Japan and South Korea, June and July 2025
8 Jul 2025 9633.5 µg/m³Japan and South Korea, June and July 2025
26 Mar 2025 8929.6 µg/m³Japan and South Korea, March 2025
9 Jul 2025 8828.8 µg/m³Japan and South Korea, June and July 2025
18 Apr 2024 8728.2 µg/m³Japan and South Korea, April 2024
3 Nov 2023 8225.6 µg/m³Japan, November 2023
8 Jul 2024 8024.9 µg/m³–
16 Jul 2026 8024.7 µg/m³–
20 May 2025 7924.2 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, Narita, 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/narita/history (accessed 13 Oct 2026).

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

Updated 2026-10-13 00:07 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).