SmogRank / United States / Oregon / Milwaukie
Milwaukie, month by month
Milwaukie, Oregon has a measured daily mean on 1,247 days since 1 January 2023. Its worst month was February 2024, at 49 US AQI (8.9 µg/m³), 866th of 2,486 cities on that month's world ranking. Its cleanest was June 2023, at 16 US AQI (2.8 µg/m³). 2025 averaged 27 US AQI (4.9 µg/m³), against 33 US AQI (5.9 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
4 months
| Month | Why |
|---|---|
| Jan 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. |
| Dec 2023 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 9 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | No day measured. The others: 25 missing from OpenAQ's archive, 3 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.
Milwaukie's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2024 | 498.9 µg/m³ | 866thof 2,486 | – |
| January 2025 | 488.6 µg/m³ | 1,264thof 2,474 | Western United States and Mexico, January and February 2025 |
| November 2024 | 468.3 µg/m³ | 1,266thof 2,624 | North-western United States and Canada, November 2024 |
| October 2024 | 458.1 µg/m³ | 786thof 2,020 | – |
| January 2026 | 437.8 µg/m³ | 1,558thof 2,617 | – |
| August 2026 | 427.5 µg/m³ | 1,859thof 2,896 | North-western United States and Canada, 4 to 22 August 2026 |
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.
Milwaukie's worst days
| Day | US AQI | Episode |
|---|---|---|
| 5 Aug 2026 | 11541.2 µg/m³ | North-western United States and Canada, 4 to 22 August 2026 |
| 4 Aug 2026 | 10135.5 µg/m³ | North-western United States and Canada, 4 to 22 August 2026 |
| 20 Aug 2023 | 9231.1 µg/m³ | North-western United States and Canada, August 2023 |
| 9 Nov 2024 | 8426.7 µg/m³ | North-western United States and Canada, November 2024 |
| 30 Jan 2025 | 8426.7 µg/m³ | Western United States and Mexico, January and February 2025 |
| 6 Sept 2024 | 8326.5 µg/m³ | North-western United States and Canada, 4 to 11 September 2024 |
| 6 Aug 2026 | 7622.4 µg/m³ | North-western United States and Canada, 4 to 22 August 2026 |
| 31 Aug 2026 | 7522.2 µg/m³ | – |
| 29 Jan 2025 | 7522.0 µg/m³ | Western United States and Mexico, January and February 2025 |
| 13 Jan 2026 | 7321.0 µg/m³ | – |
Daily means, the highest since 1 Jan 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, Milwaukie, Oregon, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/milwaukie/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.
Milwaukie now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 22:07 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).