SmogRank / Japan / Ibaraki / Mito
Mito, month by month
Mito has a measured daily mean on 814 days since 15 August 2023. Its worst month was July 2025, at 56 US AQI (11.8 µg/m³), 877th of 2,889 cities on that month's world ranking. Its cleanest was September 2026, at 30 US AQI (5.4 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
17 months
| Month | Why |
|---|---|
| Feb 2026 | 19 of 28 days measured; a month needs 20. The others: 9 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 18 of 28 days measured; a month needs 20. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jan 2025 | 8 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks. |
| Dec 2024 | 9 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks. |
| Oct 2024 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | 6 of 30 days measured; a month needs 21. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 4 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Jul 2024 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Jun 2024 | 2 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| May 2024 | 6 of 31 days measured; a month needs 22. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 12 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 18 with under 18 hours of readings or readings that failed our checks. |
| Feb 2024 | 12 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 16 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | 7 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Sep 2023 | 11 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | 3 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Mito's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2025 | 5611.8 µg/m³ | 877thof 2,889 | Japan and South Korea, June and July 2025 |
| August 2025 | 5511.4 µg/m³ | 909thof 2,901 | Japan, 4 to 5 August 2025 |
| July 2026 | 5410.6 µg/m³ | 1,211thof 2,784 | Japan, July 2026 |
| November 2023 | 5310.2 µg/m³ | 580thof 2,243 | Japan, November 2023 |
| March 2025 | 519.2 µg/m³ | 1,735thof 2,862 | – |
| April 2025 | 519.1 µg/m³ | 1,447thof 2,951 | – |
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.
Mito's worst days
| Day | US AQI | Episode |
|---|---|---|
| 7 Jul 2025 | 11039.1 µg/m³ | Japan and South Korea, June and July 2025 |
| 18 Apr 2024 | 10637.5 µg/m³ | Japan and South Korea, April 2024 |
| 9 Jul 2025 | 10637.4 µg/m³ | Japan and South Korea, June and July 2025 |
| 8 Jul 2025 | 10235.8 µg/m³ | Japan and South Korea, June and July 2025 |
| 5 Aug 2025 | 9030.3 µg/m³ | Japan, 4 to 5 August 2025 |
| 8 Jul 2024 | 8929.4 µg/m³ | Japan, 6 to 8 July 2024 |
| 21 Jul 2024 | 8728.3 µg/m³ | – |
| 26 Jun 2024 | 8527.4 µg/m³ | – |
| 7 Sept 2024 | 8426.7 µg/m³ | Japan and South Korea, September 2024 |
| 16 Jul 2026 | 8326.5 µg/m³ | Japan, July 2026 |
Daily means, the highest since 15 Aug 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, Mito, Japan, 15 Aug 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/mito/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.
Mito 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).