Air Quality in Portland, Oregon — Live
Live readings from PurpleAir sensors across Portland — with free alerts the moment smoke moves in.
AQI 28 from 5 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Portland, Oregon is AQI 28 — Good and rising — with PM2.5 at 5.1 µg/m³, the median of 5 live PurpleAir sensors reading 26 to 35. Canairy's verdict: Breathe easy.
For scale, that PM2.5 reading is below the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Pollen is quiet in Portland right now. Google's pollen forecast covers this area and shows no tree, grass or weed activity today — which is a real answer, not missing data.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Portland and Beaverton, Gresham, Lake Oswego, Vancouver. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Portland
The sensors Canairy reads in Portland agree right now — all 5 sit in the Good band, a 9-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.6 mi ESE | 26 | Good |
| 3.4 mi ENE | 35 | Good |
| 3.7 mi NNE | 28 | Good |
| 4.0 mi SE | 33 | Good |
| 5.3 mi WSW | 28 | Good |
For most of the year Portland's air is clean, cooled by ocean air pushing up the Willamette Valley. The trouble comes in two seasons: late-summer wildfire smoke, and winter, when a lid of warm air can settle over the valley and trap wood smoke and traffic exhaust near the ground for days. In September 2020, drifting smoke from fires in the Cascades gave Portland the worst air quality of any major city in the world, and the city set an all-time record AQI of 779.
What Canairy does for Portland
A clear verdict
Not just a number — a plain-English call for Portland: open the windows, or keep them shut.
Smoke alerts
A push or text the moment the air crosses your threshold — and again when it clears.
A heads-up before it's bad
Trend alerts catch the air turning, so you can close up the house before the smoke settles in.
Every place you care about
Home, work, the kids' school — across Portland or across the country, on one screen.
September 2020 was the smoke event Portland can't forget
Over Labor Day weekend in 2020, unusually strong east winds swept down the Cascades during a heatwave and exploded a string of wildfires, including the Riverside Fire in Clackamas County just east of the metro. Those same winds carried thick smoke straight into Portland. For several days the city ranked No. 1 in the world for worst air quality, ahead of famously polluted cities like Delhi and Karachi, and the smoke was thick enough that residents said it burned their throats and cut visibility to a few feet.
On September 13, 2020, Portland recorded an Air Quality Index of 779, deep in the hazardous range and far past its previous record of 166, set during the Eagle Creek Fire in September 2017. Before that year the metro had never measured worse than Unhealthy on the AQI scale; in 2020 it logged two Very Unhealthy and six Hazardous days in a single stretch, from September 10 through 17. It took a shift in the weather, not any single day, to finally clear the valley.
Most years, Portland's everyday air is clean. The risk is the smoke.
The 2020 numbers are real, but they are not the everyday picture. The American Lung Association's 2026 State of the Air report, built on 2022 to 2024 data, ranks the Portland-Vancouver-Salem metro 186th worst of 211 metros for year-round particle pollution, tied for 23rd cleanest in the country. Multnomah County passes the annual particle standard at 6.2 micrograms per cubic meter. It averaged 1.2 unhealthy particle days a year over those three years, a C grade. Ozone earned a B, at 0.3 unhealthy days a year.
Those figures show the smoke years falling out of the record. In the 2024 report, built on 2020 to 2022 data with the smoke year still in the window, Multnomah's year-round particle level stood at 8.1 micrograms per cubic meter. It dropped to 6.7 in the 2025 report, on 2021 to 2023 data, and to 6.2 in the 2026 report. The metro's weakest mark is ozone in Clackamas County, a D at 2.7 high-ozone days a year, which is why the region ranks 84th worst in the nation for ozone even as its particle numbers look good. None of this changes the geography. The Gorge winds and the winter inversions are still here, and one bad fire season would push the count back up.
The Columbia Gorge and Cascade foothills funnel smoke toward the city
Portland sits where the Willamette Valley meets the Columbia River Gorge, and that geography shapes its smoke risk. When high pressure builds east of the Cascades, air pours west through the Gorge as strong, dry east winds. Those winds fan fires in the foothills and push their smoke directly over the metro, which is exactly what happened in 2020.
It was also the story of the 2017 Eagle Creek Fire. That blaze started on September 2 when a teenager set off fireworks in the Gorge during a burn ban, and it went on to burn about 50,000 acres. Westerly shifts blew smoke and ash onto the Portland area, dropping the sun to a dim red disk and dusting cars and sidewalks like snow. Air quality reached Unhealthy on September 5 and 6, peaking at an AQI of 166 — the worst reading the metro had on record until 2020. Schools closed or canceled outdoor activities.
Winter brings a quieter, homegrown air problem
Portland's smoke season isn't only about fire. The Willamette Valley behaves like a bathtub ringed by mountains, and in winter a temperature inversion often settles a layer of warm air over the top like a lid. Cold, dense air pools on the valley floor with nowhere to go, and whatever pollution is down there, wood smoke from stoves and fireplaces, traffic exhaust, stays trapped near the ground for days until a front finally scours it out.
That's why Oregon DEQ issues particulate advisories during cold, stagnant spells, and why local jurisdictions restrict wood burning when the air stops moving. Fine-particle pollution reliably climbs from roughly October through February here, driven by household wood burning and those pollution-trapping inversions rather than by any distant fire.
Portland air quality FAQ
What is the air quality in Portland right now?
As of October 20, 2026 at 5:10 AM PDT, the air quality in Portland, Oregon is AQI 28 — Good — with PM2.5 at 5.1 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
How bad did Portland's air get during the 2020 wildfires?
In September 2020 Portland had the worst air quality of any major city in the world for several days, and on September 13 it set an all-time record AQI of 779, deep in the hazardous range. The smoke came from wildfires in the Cascades, including the Riverside Fire just east of the metro, pushed toward the city by strong east winds.
Why does Portland's air get bad in winter even when there's no fire?
The Willamette Valley sits like a bathtub ringed by mountains, and in winter a temperature inversion can put a lid of warm air over the top. Cold air and pollution, mainly wood smoke and traffic exhaust, get trapped near the ground for days. Oregon DEQ issues particulate advisories and local wood-burning restrictions during these stagnant stretches, which is why fine-particle levels tend to climb from October through February.
What the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 5 curated PurpleAir sensors Canairy tracks in and around Portland, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
Go deeper
Air quality near Portland
We watch Portland's air. You live your life.
Set your threshold once and get a heads-up only when the air actually changes for you. Free on the App Store & Google Play.