SmogRank / Japan / Gifu / Sekimachi
Sekimachi, month by month
Sekimachi has a measured daily mean on 1,025 days since 28 July 2023. Its worst month was April 2024, at 62 US AQI (15.0 µg/m³), 407th of 2,520 cities on that month's world ranking. Its cleanest was December 2024, at 33 US AQI (5.9 µg/m³).
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
5 months
| Month | Why |
|---|---|
| May 2025 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Apr 2025 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Mar 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | No day measured. The others: 28 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.
Sekimachi's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2024 | 6215.0 µg/m³ | 407thof 2,520 | Japan and South Korea, April 2024 |
| July 2025 | 5913.2 µg/m³ | 603rdof 2,889 | Japan and South Korea, June and July 2025 |
| August 2025 | 5812.7 µg/m³ | 633rdof 2,901 | – |
| September 2025 | 5611.9 µg/m³ | 471stof 3,104 | – |
| February 2026 | 5611.6 µg/m³ | 1,089thof 2,866 | Japan, 23 February 2026 |
| November 2025 | 5511.2 µg/m³ | 848thof 2,715 | – |
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.
Sekimachi's worst days
| Day | US AQI | Episode |
|---|---|---|
| 19 Apr 2024 | 11842.6 µg/m³ | Japan and South Korea, April 2024 |
| 9 Jul 2025 | 9633.0 µg/m³ | Japan and South Korea, June and July 2025 |
| 18 Apr 2024 | 9532.5 µg/m³ | Japan and South Korea, April 2024 |
| 23 Feb 2026 | 8929.7 µg/m³ | Japan, 23 February 2026 |
| 5 Nov 2023 | 8829.0 µg/m³ | Japan, November 2023 |
| 2 Jul 2025 | 8829.0 µg/m³ | Japan and South Korea, June and July 2025 |
| 3 Jul 2025 | 8527.6 µg/m³ | Japan and South Korea, June and July 2025 |
| 20 Apr 2024 | 8527.2 µg/m³ | Japan and South Korea, April 2024 |
| 17 Apr 2024 | 8427.0 µg/m³ | Japan and South Korea, April 2024 |
| 4 Nov 2023 | 8426.7 µg/m³ | Japan, November 2023 |
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, Sekimachi, 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/sekimachi/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.
Sekimachi now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).