Air Quality in Hillsboro, Oregon — Live
Live readings from PurpleAir sensors across Hillsboro — with free alerts the moment the air turns.
AQI 46 from 5 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Hillsboro, Oregon is AQI 46 — Good and rising — with PM2.5 at 8.4 µg/m³, the median of 5 live PurpleAir sensors reading 24 to 51. 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 today in Hillsboro: weeds pollen is the strongest of the three at a low level, from Google's pollen forecast. Canairy shows the tree, grass and weed forecast beside the air reading on every plan, including the free one.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Hillsboro and Beaverton, Aloha, Cornelius, Forest Grove. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Hillsboro
The sensors Canairy reads in Hillsboro are 27 AQI points apart right now, from Good to Moderate, which is the whole reason one city-wide number can mislead you: the median describes air you may not be standing in.
| From city center | AQI | Category |
|---|---|---|
| 0.8 mi WSW | 46 | Good |
| 1.6 mi SSW | 24 | Good |
| 2.7 mi ENE | 44 | Good |
| 5.9 mi ENE | 51 | Moderate |
| 7.5 mi SE | 47 | Good |
Hillsboro sits on the flat floor of the Tualatin Valley about 17 miles west of Portland, on ground that was farmland long before it became the center of Oregon's Silicon Forest. Most people assume the air question here is about the chip fabs. The state's own monitoring says otherwise: the DEQ air monitor near Hare Field has measured days over the federal fine-particle standard, and DEQ attributes most of that pollution to wood stove smoke rather than industry. The fabs are a separate and real conversation, and this page covers both.
What Canairy does for Hillsboro
A clear verdict
Not just a number — a plain-English call for Hillsboro: 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 Hillsboro or across the country, on one screen.
Most of what the Hare Field monitor picks up is wood smoke
Washington County has two regulatory air monitors, and the one in Hillsboro near Hare Field is the one that has caused trouble. It recorded days above the federal 24-hour PM2.5 standard in 2011 and again in 2013 — enough that DEQ warned publicly the area could end up designated nonattainment, which would have carried real consequences for industrial permitting. The three-year average that actually determines the designation stayed below the limit, and 2014 data suggested the local response was working.
DEQ's answer to the obvious question is blunt: most of the PM2.5 pollution is primarily caused by woodstove smoke. The agency put woodstoves in the area at roughly 1,380 tons of fine particles a year, against the 31 tons a year Intel had requested under its permit. The monitor also shows the pattern you would expect from home heating — levels climbing in the evening as people get home and light a fire — and the worst readings come on cold winter nights when a weather inversion and stagnant air stop anything from dispersing.
Where Intel actually fits in
Intel's two Washington County campuses — Gordon Moore Park at Ronler Acres on NE Century Boulevard in Hillsboro, and the Aloha campus on SW 198th Avenue — have run under a single Standard Air Contaminant Discharge Permit since 2016, modified in 2022 and again in 2024. DEQ issued the current version on April 16, 2024, after a public comment period from January 10 to March 8 and a hearing in February, approving additional cleanroom space and higher emission limits. That permit requires Intel to test for PM2.5 beginning in 2027, and to run ambient monitoring for nitrogen oxides and PM2.5 at the property boundary for three years starting in 2028.
Intel has also been called into Cleaner Air Oregon, the state's health-risk-based air toxics program, which requires a facility to inventory its toxic emissions, assess the health risk to the people living nearby, and reduce that risk if it exceeds legal limits. Intel has been working through the emissions inventory stage since May 2025 — natural gas combustion units, cooling towers, emergency generators and fire pumps, storage tanks — with the risk assessment still ahead. There is history behind the scrutiny: in 2023 DEQ cited three Class II permit violations at Ronler Acres after a caustic injector on an acid gas scrubber sat in hold status for nine weeks in the summer of 2022, leaving the plant non-compliant for at least 63 days on controls for hydrogen fluoride and hydrogen chloride. Worth saying plainly: neighborhood sensors measure fine particles. They do not measure hydrogen fluoride, and no consumer sensor does.
Burn season in the Tualatin Valley
Washington County's open-burning rules split the county into zones. In the restricted areas — most incorporated cities and rural fire protection districts — domestic yard-debris burning is allowed only from March 1 through June 15 and October 1 through December 15, in daylight, between 7:30 a.m. and two hours before sunset. In the prohibited zone nearer Portland you need a letter permit from DEQ. Agricultural burning is allowed in Washington County, subject to whatever local jurisdictions and the State Fire Marshal require, and industrial and commercial open burning is prohibited outright without a letter permit.
Those two burning windows land at the start and the end of the wet season, which is also when still, damp evenings are common in the valley. So a smoky evening around Hillsboro in mid-October has three plausible explanations — a legal debris pile, an early wood stove, or smoke that has drifted in from somewhere else entirely — and the only way to tell how much of it is reaching your street is to look at a sensor near you.
Hillsboro air quality FAQ
What is the air quality in Hillsboro right now?
As of September 10, 2026 at 5:09 AM PDT, the air quality in Hillsboro, Oregon is AQI 46 — Good — with PM2.5 at 8.4 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why is there smoke in Hillsboro today?
In summer and early fall it is usually wildfire smoke that has drifted into the Willamette Valley from somewhere else. The rest of the year the likeliest answer is much closer to home. DEQ says most of the PM2.5 measured at the Hillsboro monitor comes from woodstove smoke, and the readings rise in the evening as people get home and light fires. Backyard yard-debris burning is also legal in parts of Washington County from March 1 to June 15 and October 1 to December 15, which covers a lot of the smoky-evening season.
Does Intel affect Hillsboro's air quality?
Intel is a permitted air-emissions source and DEQ regulates it as one. Its Hillsboro and Aloha campuses run under a Standard Air Contaminant Discharge Permit that DEQ reissued on April 16, 2024, allowing more cleanroom space and higher emissions, with required PM2.5 testing starting in 2027 and three years of property-boundary monitoring for nitrogen oxides and PM2.5 starting in 2028. Intel is also going through Cleaner Air Oregon, the state's health-risk-based air toxics program, and has been in the emissions inventory stage since May 2025. For fine particles specifically, though, DEQ's own comparison put woodstoves at roughly 1,380 tons a year against the 31 tons a year Intel requested.
When is it legal to burn yard debris around Hillsboro?
In the restricted areas of Washington County — which covers most incorporated cities and rural fire protection districts — domestic yard-debris burning is allowed March 1 through June 15 and October 1 through December 15, during daylight between 7:30 a.m. and two hours before sunset. Closer to Portland, in the prohibited zone, you need a letter permit from DEQ. Local fire districts set their own rules on top of that, so check with yours before you light anything.
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 Hillsboro, 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
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Air quality near Hillsboro
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