Air Quality in Hillsboro, Oregon — Live

Live readings from PurpleAir sensors across Hillsboro — with free alerts the moment the air turns.

Live Hillsboro AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Hillsboro and Beaverton, Aloha, Cornelius, Forest Grove.

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.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

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

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.

What is the air quality in Hillsboro right now?

This page shows the current AQI for Hillsboro, calculated from PurpleAir sensors across the city and updated continuously. On a winter inversion night the difference between one neighborhood and the next can be substantial, so the map below shows every live sensor rather than a single citywide figure.

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 AQI level is unhealthy?

Under the US EPA scale, AQI 0–50 is Good and 51–100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups — kids, older adults, and people with asthma or heart conditions — and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

Get Canairy free on Google Play.