Portland, Oregon Air Quality
Portland has a median AQI of 38, earning an air quality grade of A — excellent air quality that ranks better than 70% of US cities. Air quality has been trending worse over the past decade, a concern for local residents and health officials. Ground-level ozone is the primary concern, typically peaking on warm sunny days due to vehicle and industrial emissions. In 2025, Portland recorded 150 good air quality days (82% of monitored days).
Population: 2,115,140 • County: Multnomah
Current AQI
Quick Facts
| Current AQI | 13 — Good |
| Air Quality Grade | A |
| Median AQI (2025) | 38 |
| vs. U.S. Cities | Better than 70% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 0 |
| 10-Year Trend | ↓ Worsening |
| Data Source | EPA AQS (historical) · AirNow (live) |
Health Recommendation
Air quality is satisfactory, and air pollution poses little or no risk.
It's a great day to be active outside!
5-Day AQI Forecast
Last 90 Days
Current Pollutant Levels
Real-time data from EPA AirNow
Local Air Quality Context
Air quality data for Portland is sourced from the Portland Lincoln High School monitoring area, located approximately 2 miles from city center. This EPA-certified station continuously tracks ground-level ozone, the primary driver of air quality alerts in this area.
Major roadways in the area include I-5, I-84, I-205, US-26, and OR-99W. Heavy vehicle traffic on these corridors is a primary source of nitrogen dioxide, carbon monoxide, and fine particulate matter (PM2.5).
Key local pollution sources include vehicle traffic, wood-burning stoves, wildfire smoke, Columbia River shipping, and industrial northwest Portland.
Wildfire smoke is a significant factor in Portland's air quality, with regional fires capable of pushing AQI from Good to Unhealthy within hours during fire season (typically July through October). On smoke-impacted days, staying indoors with windows closed and running an air purifier with a HEPA filter is the most effective protection.
AQI Trend (10 Years)
Air Quality Days by Year
Portland Median AQI by Year
Annual EPA air quality data for Portland — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 38 | 150 | — | 87 | Ozone |
| 2024 | 35 | 311 | — | 93 | Ozone |
| 2023 | 38 | 267 | 1 | 117 | PM2.5 |
| 2022 | 36 | 266 | 5 | 165 | PM2.5 |
| 2021 | 36 | 294 | 1 | 105 | Ozone |
| 2020 | 36 | 275 | 9 | 779 | Ozone |
| 2019 | 36 | 283 | — | 91 | PM2.5 |
| 2018 | 37 | 272 | 9 | 152 | Ozone |
| 2017 | 38 | 278 | 6 | 166 | PM2.5 |
| 2016 | 33 | 324 | 1 | 108 | Ozone |
Source: EPA Air Quality System (AQS) annual summaries. "Unhealthy Days" includes Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous categories.
2025 Air Quality Summary
Primary Pollutant Days (2025)
Days when each pollutant was the primary driver of AQI. Learn about pollutants →
Frequently Asked Questions About Portland Air Quality
What is the air quality in Portland today?
The current AQI in Portland is 13, rated "Good". Air quality is good — outdoor activity is safe for everyone today. Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Portland getting better or worse?
Air quality in Portland has been worsening. The median AQI has risen 5 points (from 33 in 2016 to 38 in 2025), a concern for local health officials.
What is the most common air pollutant in Portland?
Ozone is the primary air pollutant in Portland, responsible for 114 days (63% of monitored days) in 2025. Ground-level ozone forms when sunlight reacts with emissions from vehicles and industry, typically peaking on hot summer afternoons.
How many unhealthy air days does Portland have per year?
In 2025, Portland recorded 82% good air quality days (150 days) out of 182 monitored days. There were 0 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 87.
What air quality grade does Portland receive?
Portland receives an air quality grade of A, placing it better than 70% of US cities. This is based on a median AQI of 38 in 2025, with 150 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 70% of US cities
Nearby Cities
Get AQI Alerts
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National Rankings
See how Portland compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Portland
Ozone is Portland's primary pollutant. Standard HEPA filters don't capture ozone molecules — you need activated carbon or PECO technology to chemically break them down. We highlight those units here.
Blueair Blue Pure 211+
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Other Great Options
Molekule Air Pro
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Honeywell HPA300
Powerful workhorse for large rooms. Built to last.
RabbitAir MinusA2
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Not sure which air purifier is right for you?
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Read our complete buying guide →