SmogRank / Japan / Gifu / Mizuho
Mizuho, month by month
Mizuho has a measured daily mean on 1,035 days since 28 July 2023. Its worst month was July 2025, at 57 US AQI (12.2 µg/m³), 791st of 2,889 cities on that month's world ranking. Its cleanest was January 2024, at 27 US AQI (4.8 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
6 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. |
| Jan 2025 | 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.
Mizuho's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2025 | 5712.2 µg/m³ | 791stof 2,889 | Japan and South Korea, June and July 2025 |
| April 2024 | 5511.5 µg/m³ | 793rdof 2,520 | Japan and South Korea, April 2024 |
| August 2025 | 5511.3 µg/m³ | 936thof 2,901 | – |
| July 2026 | 5511.1 µg/m³ | 1,089thof 2,784 | – |
| June 2025 | 5310.4 µg/m³ | 1,179thof 2,508 | Japan and South Korea, June and July 2025 |
| March 2026 | 5310.1 µg/m³ | 1,648thof 2,971 | – |
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.
Mizuho's worst days
| Day | US AQI | Episode |
|---|---|---|
| 2 Jul 2025 | 10135.5 µg/m³ | Japan and South Korea, June and July 2025 |
| 9 Jul 2025 | 9532.7 µg/m³ | Japan and South Korea, June and July 2025 |
| 21 Dec 2024 | 9030.3 µg/m³ | – |
| 4 Nov 2023 | 8829.0 µg/m³ | Japan, November 2023 |
| 1 Jul 2025 | 8728.2 µg/m³ | Japan and South Korea, June and July 2025 |
| 3 Jul 2025 | 8326.3 µg/m³ | Japan and South Korea, June and July 2025 |
| 18 Apr 2024 | 8226.0 µg/m³ | Japan and South Korea, April 2024 |
| 5 Nov 2023 | 8125.3 µg/m³ | Japan, November 2023 |
| 9 Dec 2023 | 8024.9 µg/m³ | – |
| 19 Apr 2024 | 8024.7 µg/m³ | Japan and South Korea, April 2024 |
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, Mizuho, 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/mizuho/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.
Mizuho now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).