SmogRank / United States / Ohio / Oregon
Oregon, month by month
Oregon has a measured daily mean on 868 days since 12 March 2024. Its worst month was July 2026, at 97 US AQI (33.6 µg/m³), 98th of 2,784 cities on that month's world ranking. Its cleanest was October 2025, at 33 US AQI (6.0 µg/m³). 2025 averaged 52 US AQI (9.8 µg/m³), against 52 US AQI (9.6 µg/m³) in 2024.
Every month since 2024
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
3 months
| Month | Why |
|---|---|
| Aug 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 19 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Oregon's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2026 | 9733.6 µg/m³ | 98thof 2,784 | Northern United States and Canada, July 2026 North-eastern United States, June and July 2026 |
| June 2025 | 6616.9 µg/m³ | 315thof 2,508 | Northern United States and Canada, June 2025 Northern United States and Canada, May and June 2025 |
| February 2026 | 6114.2 µg/m³ | 836thof 2,866 | North-eastern United States and Canada, 14 to 19 February 2026 North-eastern United States and Canada, 2 to 3 February 2026 |
| July 2024 | 5612.0 µg/m³ | 428thof 2,566 | North-eastern United States and Canada, July 2024 |
| August 2024 | 5511.4 µg/m³ | 400thof 2,010 | – |
| December 2024 | 5511.3 µg/m³ | 735thof 2,616 | – |
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.
Oregon's worst days
| Day | US AQI | Episode |
|---|---|---|
| 16 Jul 2026 | 500+377.0 µg/m³ | Northern United States and Canada, July 2026 |
| 17 Jul 2026 | 282207.0 µg/m³ | Northern United States and Canada, July 2026 |
| 6 Jun 2025 | 13549.2 µg/m³ | Northern United States and Canada, May and June 2025 |
| 19 Jul 2026 | 11741.8 µg/m³ | Northern United States and Canada, July 2026 |
| 8 Jun 2025 | 11541.0 µg/m³ | Northern United States and Canada, May and June 2025 |
| 20 Jul 2026 | 11139.4 µg/m³ | Northern United States and Canada, July 2026 |
| 15 Feb 2026 | 9532.5 µg/m³ | North-eastern United States and Canada, 14 to 19 February 2026 |
| 7 Jun 2025 | 9331.5 µg/m³ | Northern United States and Canada, May and June 2025 |
| 16 Feb 2026 | 8929.7 µg/m³ | North-eastern United States and Canada, 14 to 19 February 2026 |
| 5 Jun 2025 | 8929.5 µg/m³ | Northern United States and Canada, May and June 2025 |
Daily means, the highest since 12 Mar 2024; 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, Oregon, United States, 12 Mar 2024 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/oregon/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.
Oregon now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 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).