SmogRank / United States / Oregon / Corvallis

Corvallis, month by month

Corvallis, Oregon has a measured daily mean on 1,220 days since 1 January 2023. Its worst month was August 2026, at 51 US AQI (9.1 µg/m³), 1,155th of 2,896 cities on that month's world ranking. Its cleanest was May 2025, at 10 US AQI (1.8 µg/m³). 2025 averaged 18 US AQI (3.3 µg/m³), against 18 US AQI (3.3 µg/m³) in 2024.

Every month since 2023

202622 so far267 days measured2,750th of 2,791 in the world
Jan34#2,081Feb18#2,808Mar14#2,950Apr15#2,902May16#2,823Jun14#2,460Jul16#2,761Aug51#1,155Sep17#2,899Oct15#2,689
202518 for the year327 days measured2,669th of 2,681 in the world
Jan26#2,295Feb13#2,623Mar10#2,858Apr11#2,947May10#2,822Jun13#2,501Jul16#2,857Aug21 daysSep26#2,768Oct20#2,494Nov34#2,155Dec23#2,847
202418 for the year334 days measured2,078th of 2,097 in the world
Jan19 daysFeb14#2,455Mar14#1,667Apr12#2,492May12#2,650Jun13#2,535Jul17#2,522Aug22#1,964Sep22#1,926Oct21#1,952Nov29#2,239Dec31#2,174
202321 for the year292 days measured1,336th of 1,355 in the world
Jan21 daysFeb1 dayMar9 daysApr16#1,579May19#1,565Jun17#1,565Jul19#1,374Aug40#1,258Sep20#2,124Oct15#1,992Nov21#2,154Dec13#2,232
Each square is a month's mean PM2.5 in US AQI from Corvallis'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 Corvallis 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

5 months
MonthWhy
Aug 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jan 202419 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Mar 20239 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 20231 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks.
Jan 202321 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 4 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.

Corvallis's worst months

MonthUS AQIDays measuredWorld rankEpisode
August 2026 519.1 µg/m³30 of 311,155thof 2,896North-western United States and Canada, 4 to 22 August 2026
August 2023 407.2 µg/m³31 of 311,258thof 1,980North-western United States and Canada, August 2023
November 2025 346.1 µg/m³24 of 302,155thof 2,715–
January 2026 346.1 µg/m³31 of 312,081stof 2,617–
December 2024 315.6 µg/m³24 of 312,174thof 2,616–
November 2024 295.2 µg/m³27 of 302,239thof 2,624–

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.

Corvallis's worst days

DayUS AQIEpisode
5 Aug 2026 15966.7 µg/m³North-western United States and Canada, 4 to 22 August 2026
4 Aug 2026 15864.9 µg/m³North-western United States and Canada, 4 to 22 August 2026
6 Aug 2026 9633.1 µg/m³North-western United States and Canada, 4 to 22 August 2026
20 Aug 2023 8527.2 µg/m³North-western United States and Canada, August 2023
27 Jan 2026 7722.8 µg/m³–
25 Aug 2023 7622.4 µg/m³North-western United States and Canada, August 2023
6 Sept 2024 7120.0 µg/m³–
26 Jan 2023 6617.2 µg/m³–
26 Aug 2023 6617.2 µg/m³North-western United States and Canada, August 2023
3 Aug 2026 6616.9 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, Corvallis, 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/corvallis/history (accessed 12 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.

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

Updated 2026-10-12 19:07 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).