SmogRank / Japan / Iwate / Kuji
Kuji, month by month
Kuji has a measured daily mean on 1,128 days since 28 July 2023. Its worst month was March 2026, at 53 US AQI (10.0 µg/m³), 1,675th of 2,971 cities on that month's world ranking. Its cleanest was December 2024, at 19 US AQI (3.4 µg/m³). 2025 averaged 33 US AQI (6.0 µg/m³), against 33 US AQI (5.9 µg/m³) in 2024.
Every month since 2023
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
2 months
| Month | Why |
|---|---|
| Jan 2026 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 4 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.
Kuji's worst months
| Month | US AQI | World rank |
|---|---|---|
| March 2026 | 5310.0 µg/m³ | 1,675thof 2,971 |
| April 2024 | 519.3 µg/m³ | 1,107thof 2,520 |
| July 2025 | 488.7 µg/m³ | 1,588thof 2,889 |
| July 2024 | 458.1 µg/m³ | 1,307thof 2,566 |
| March 2025 | 448.0 µg/m³ | 1,927thof 2,862 |
| June 2024 | 447.9 µg/m³ | 1,358thof 2,563 |
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.
Kuji's worst days
| Day | US AQI |
|---|---|
| 27 Apr 2024 | 8125.2 µg/m³ |
| 30 Mar 2026 | 7622.4 µg/m³ |
| 24 Mar 2026 | 7522.2 µg/m³ |
| 26 Apr 2025 | 7421.4 µg/m³ |
| 4 Jul 2025 | 7320.7 µg/m³ |
| 2 Mar 2025 | 6918.8 µg/m³ |
| 1 Mar 2025 | 6717.9 µg/m³ |
| 17 Mar 2026 | 6717.5 µg/m³ |
| 18 Apr 2024 | 6617.3 µg/m³ |
| 25 Mar 2025 | 6617.0 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, Kuji, 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/kuji/history (accessed 12 Oct 2026).
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.
Kuji now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 22:07 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).