SmogRank / United States / Oregon / Oregon City

Oregon City, month by month

Oregon City has a measured daily mean on 474 days since 28 May 2025. Its worst month was August 2026, at 57 US AQI (12.4 µg/m³), 526th of 2,896 cities on that month's world ranking. Its cleanest was June 2026, at 17 US AQI (3.1 µg/m³).

Every month since 2025

202629 so far277 days measured2,613th of 2,798 in the world

Jan52#1,173 Feb29#2,557 Mar19#2,869 Apr19#2,809 May21#2,713 Jun17#2,412 Jul22#2,701 Aug57#526 Sep19#2,883 Oct22#2,517

2025too few days for a mean (a year needs 256)197 days measured

JanFebMarAprMay4 daysJun20#2,444 Jul17#2,842 Aug24#2,776 Sep33#2,136 Oct34#1,558 Nov44#1,569 Dec32#2,530

Each square is a month's mean PM2.5 in US AQI from Oregon City's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Oregon City marked; each year, the year's. A dashed square is the running month, so far.

Good0–50

Moderate51–100

Sensitive groups101–150

Unhealthy151–200

Very unhealthy201–300

Hazardous301+

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

1 month

Month	Why
May 2025	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.

Oregon City's worst months

Month	US AQI	Days measured	World rank	Episode
August 2026	5712.4 µg/m³	30 of 31	526thof 2,896	North-western United States and Canada, 4 to 22 August 2026
January 2026	529.4 µg/m³	31 of 31	1,173rdof 2,617	–
November 2025	447.9 µg/m³	24 of 30	1,569thof 2,715	–
October 2025	346.1 µg/m³	31 of 31	1,558thof 2,614	–
September 2025	335.9 µg/m³	30 of 30	2,136thof 3,104	–
December 2025	325.7 µg/m³	29 of 31	2,530thof 3,006	–

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 City's worst days

Day	US AQI	Episode
5 Aug 2026	17386.2 µg/m³	North-western United States and Canada, 4 to 22 August 2026
4 Aug 2026	16270.5 µg/m³	North-western United States and Canada, 4 to 22 August 2026
6 Aug 2026	14252.2 µg/m³	North-western United States and Canada, 4 to 22 August 2026
31 Aug 2026	9834.2 µg/m³	–
26 Jan 2026	7723.1 µg/m³	–
25 Jan 2026	7321.0 µg/m³	–
27 Jan 2026	7120.0 µg/m³	–
12 Nov 2025	6818.0 µg/m³	–
10 Jan 2026	6717.5 µg/m³	–
31 Oct 2025	6617.2 µg/m³	–

Daily means, the highest since 28 May 2025; 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 City, United States, 28 May 2025 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/oregon-city/history (accessed 13 Oct 2026).

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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 City now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-13 01:07 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).