SmogRank / Japan / Wakayama / Arida
Arida, month by month
Arida has a measured daily mean on 900 days since 28 July 2023. Its worst month was April 2025, at 62 US AQI (14.9 µg/m³), 549th of 2,951 cities on that month's world ranking. Its cleanest was October 2024, at 33 US AQI (5.9 µg/m³). 2025 averaged 54 US AQI (10.7 µg/m³), against 45 US AQI (8.1 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
11 months
| Month | Why |
|---|---|
| Aug 2026 | 3 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jul 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jun 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Mar 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Feb 2026 | No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 13 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Mar 2025 | 7 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 13 of 28 days measured; a month needs 20. The others: 15 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.
Arida's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2025 | 6214.9 µg/m³ | 549thof 2,951 | Japan, 30 April 2025 Japan and South Korea, April 2025 |
| July 2025 | 5913.2 µg/m³ | 603rdof 2,889 | Japan and South Korea, June and July 2025 |
| August 2025 | 5913.2 µg/m³ | 542ndof 2,901 | Japan, 25 to 27 August 2025 |
| April 2024 | 5812.8 µg/m³ | 616thof 2,520 | Japan and South Korea, April 2024 |
| March 2024 | 5712.2 µg/m³ | 253rdof 1,698 | – |
| June 2025 | 5712.2 µg/m³ | 774thof 2,508 | Japan and South Korea, June and July 2025 |
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.
Arida's worst days
| Day | US AQI | Episode |
|---|---|---|
| 18 Apr 2024 | 15459.9 µg/m³ | Japan and South Korea, April 2024 |
| 5 Jul 2025 | 14553.4 µg/m³ | Japan and South Korea, June and July 2025 |
| 9 Jul 2025 | 10537.0 µg/m³ | Japan and South Korea, June and July 2025 |
| 8 Jul 2025 | 10235.9 µg/m³ | Japan and South Korea, June and July 2025 |
| 1 Feb 2025 | 9934.9 µg/m³ | Japan and South Korea, 31 January to 1 February 2025 |
| 31 Jan 2025 | 9633.0 µg/m³ | Japan and South Korea, 31 January to 1 February 2025 |
| 6 Jul 2025 | 8627.8 µg/m³ | Japan and South Korea, June and July 2025 |
| 30 Apr 2025 | 8527.6 µg/m³ | Japan, 30 April 2025 |
| 23 Jan 2025 | 8527.1 µg/m³ | Japan and South Korea, 17 to 24 January 2025 |
| 26 Apr 2025 | 8527.1 µg/m³ | Japan and South Korea, April 2025 |
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, Arida, 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/arida/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.
Arida 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).