SmogRank / Japan / Toyama / Namerikawa
Namerikawa, month by month
Namerikawa has a measured daily mean on 868 days since 28 July 2023. Its worst month was April 2024, at 60 US AQI (14.0 µg/m³), 484th of 2,520 cities on that month's world ranking. Its cleanest was December 2025, at 18 US AQI (3.2 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
11 months
| Month | Why |
|---|---|
| Oct 2026 | No day measured. The others: 11 with no readings from the monitor, 1 with under 18 hours of readings or readings that failed our checks. |
| Sep 2026 | 9 of 30 days measured; a month needs 21. The others: 6 with no readings from the monitor, 14 with readings for part of the day (a day needs 18 hours), 1 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Sep 2025 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Aug 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 9 of 31 days measured; a month needs 22. The others: 22 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.
Namerikawa's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2024 | 6014.0 µg/m³ | 484thof 2,520 | Japan and South Korea, April 2024 |
| June 2024 | 5611.8 µg/m³ | 371stof 2,563 | – |
| March 2024 | 5310.2 µg/m³ | 383rdof 1,698 | – |
| May 2024 | 519.3 µg/m³ | 906thof 2,684 | – |
| July 2024 | 519.2 µg/m³ | 951stof 2,566 | – |
| March 2025 | 519.2 µg/m³ | 1,735thof 2,862 | Japan and South Korea, March 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.
Namerikawa's worst days
| Day | US AQI | Episode |
|---|---|---|
| 18 Apr 2024 | 9029.8 µg/m³ | Japan and South Korea, April 2024 |
| 26 Mar 2025 | 8326.4 µg/m³ | Japan and South Korea, March 2025 |
| 19 Apr 2024 | 8326.3 µg/m³ | Japan and South Korea, April 2024 |
| 25 Mar 2025 | 8024.4 µg/m³ | Japan and South Korea, March 2025 |
| 14 Jun 2024 | 7522.1 µg/m³ | – |
| 29 Apr 2024 | 7321.1 µg/m³ | – |
| 13 Jun 2024 | 7321.0 µg/m³ | – |
| 16 Nov 2024 | 7320.8 µg/m³ | – |
| 30 Mar 2024 | 7220.6 µg/m³ | – |
| 29 Jul 2023 | 7220.2 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, Namerikawa, Japan, 28 Jul 2023 – 22 Sep 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/namerikawa/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.
Namerikawa 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).