Hillsboro Real-Time AQI Tracker
Get Alerts For Unhealthy AQI In Your Area
When air quality in your area reaches unhealthy levels, we'll send you a quick alert, along with expert tips on how to reduce your exposure.
What's Actually In Hillsboro Air Today?
What High AQI Means for Your Lungs in Hillsboro
How to Read AQI
The Air Quality Index (AQI) measures how polluted the air is and how it may affect your health.
0–50 (Good): Air quality is satisfactory.
51–100 (Moderate): Acceptable, but some pollutants may pose minor concerns.
101–150 (Unhealthy for Sensitive Groups)
151–200 (Unhealthy)
201–300 (Very Unhealthy)
301+ (Hazardous)
Moderate
Still okay for most, but if you have asthma or allergies, take it easy and avoid long outdoor workouts.
Shop MERV 11 filters→What's the Right Filter for Your AQI Level?
Check Today's Live Real Time Air Quality Index AQI Map in Hillsboro, OR Now
TL;DR
The live map above shows Hillsboro's current Air Quality Index (AQI), its color and the pollutant behind it. Most days the air in Hillsboro, Oregon, is clean; the rough patches come from winter wood smoke, summer ozone and late-season wildfire smoke. If fine particles (PM2.5) push the reading to 100, switch to a MERV 13 filter, set the thermostat fan to On, run a HEPA cleaner in each occupied room and close up the house. For ozone, exercise early instead.
Key Takeaways
Hillsboro's official fine-particle (PM2.5) reading comes from an Oregon DEQ monitor at Hare Field on NE Grant Street.
Hillsboro bans fireplace and wood stove use on red days from November 1 to March 1.
Lead from piston planes at Hillsboro Airport is not part of the AQI, so the live map cannot show it.
Reading Hillsboro's Live AQI Map in 30 Seconds
The map boils the latest monitor data down to one number on the U.S. EPA's 0 to 500 AQI scale, plus a color and a pollutant label. Read the pollutant first, then the number and time stamp. The pollutant decides your next move, since PM2.5 usually points to smoke and ozone to a hot afternoon.
Oregon DEQ's 2026 monitoring network plan places a PM2.5 monitor at Hillsboro Hare Field, 1151 NE Grant Street. That site doesn't measure ozone, so Hillsboro ozone readings rely on metro stations such as Tualatin. Compare the Beaverton, Portland or Oregon live AQI maps.
AQI Colors and the Right Response for a Hillsboro Household
Find the map's color, then read across its row. AQI 100 is Filterbuy's action line for smoke: switch to MERV 13, set the thermostat fan to On, run a HEPA cleaner in each occupied room and close the house. More in our AQI above 100 guide.
Hillsboro AQI Categories and What to Do
| AQI | Category | What to do in Hillsboro |
|---|---|---|
| 0–50 | Good (green) | Open windows; enjoy Orenco Woods or the Rock Creek Trail. |
| 51–100 | Moderate (yellow) | Most people are fine. At 100, switch to MERV 13 and set the fan to On. |
| 101–150 | Unhealthy for Sensitive Groups (orange) | Sensitive groups cut back. Windows shut; HEPA in occupied rooms. |
| 151–200 | Unhealthy (red) | Everyone limits exertion. Check the filter often; keep spares. |
| 201–300 | Very Unhealthy (purple) | Follow AirNow and DEQ first. Use a clean room; filtration is one layer. |
| 301+ | Hazardous (maroon) | Official guidance first: stay indoors; heed clean-air-center notices. |
EPA categories. Filterbuy acts at 100, the top of Moderate.
Why the Map Can Lag the Smoke You See Over the Valley
When the sky looks hazy but the map still shows yellow, the gap is usually timing. AirNow reports particles as a NowCast AQI, which weights up to 12 hours of data, so smoke that rolls in after dinner can take hours to show up fully.
One regulatory monitor also covers a city that stretches from Orenco Station to Jackson Bottom. If you smell smoke, act first, then check nearby sensors on the AirNow Fire and Smoke Map.
Should Your Hillsboro Workout Move Indoors Today?
At 100 or below, outdoor plans suit nearly everyone. Between 101 and 150, children and teens, adults over 65, pregnant people, outdoor workers and anyone with heart or lung disease should cut back on hard exertion. Above 150, everyone should.
DEQ says ozone peaks in the afternoon and early evening, so a 7 a.m. run on the Rock Creek Trail beats a 5 p.m. one. Smoke has no better hour, so take the workout inside. If you start coughing or your chest feels tight, head in.
Where Hillsboro's Air Alerts and Burn Status Come From
Oregon DEQ's Portland-metro advisories cover Washington County. In August 2026, DEQ posted a smoke advisory on August 3 and an ozone advisory two days later. Keep these tools handy:
AirNow: today's and tomorrow's AQI forecast for your ZIP code.
Oregon DEQ Air Quality Index: station readings and the free OregonAIR app.
Washington County air pollution page: red-day status, the 503-846-8744 line and PublicAlerts sign-up.
What Drives Hillsboro's Air From Season to Season
Two pollutants drive Hillsboro's AQI, fine particles (PM2.5) and ozone. Washington County public health describes the county as a bowl-shaped valley where pollution can get trapped. Filterbuy's tip: a January PM2.5 reading looks just like an August one on the map, but the month usually tells you whether it's wood smoke or wildfire smoke.
Winter wood smoke. On cold, still nights, chimney smoke pools near the ground. That's what happened in November 2018, when an inversion trapped wood smoke and the county issued a red day alert. Hillsboro also bans yard debris burning year-round.
Summer ozone. Ground-level ozone forms when exhaust reacts with heat and sunlight, and regional traffic, including US 26, feeds it on hot, still days. The American Lung Association's State of the Air 2026 ranked the Portland-Vancouver metro 84th worst for ozone, with a D in Clackamas County.
Wildfire smoke. Late summer brings regional fire smoke, which shows up as PM2.5; the Portland wildfire smoke map tracks plumes.
Hillsboro's Air-Year Calendar
| Months | Main driver | First move |
|---|---|---|
| Nov–Feb | Wood smoke (PM2.5) | Check red-day status before lighting a fire. |
| Mar–May | Tree and grass pollen (not in AQI) | MERV 11 captures more pollen. |
| Jun–Aug | Ozone | Exercise early; recheck the map midafternoon. |
| Jul–Oct | Wildfire smoke (PM2.5) | At 100: MERV 13, fan On, HEPA per room, house closed. |
Typical patterns only; the live map takes priority.
The Airport Pollutant the AQI Map Leaves Out
Lead isn't part of the AQI, so the map never shows it. That matters here because Hillsboro Airport serves piston-engine planes that still burn leaded fuel, and in 2023 EPA issued a final finding that lead from these engines contributes to air pollution that may endanger public health.
Oregon State University researchers tested moss on street trees near the Hillsboro and Troutdale airports. According to a study summary, moss near Hillsboro's main runway held up to seven times Portland's urban lead background, and Hillsboro's peaks topped Troutdale's. No AQI color flags this, the moss can't show what residents inhale, and lead also settles into soil.
Smoke Days in Washington County and What an Advisory Changes
Wildfire smoke brings Hillsboro's worst air. During the September 2020 Labor Day fires, the Chehalem Mountains and Powerline fires burned in and near Washington County. The county expected unhealthy to hazardous air through at least September 17, and Portland's AQI set a record of 477 (Oregon DEQ and LRAPA).
Follow AirNow and DEQ guidance first. Then, at 100, take these steps in order:
1. Install a MERV 13 filter.
2. Set the thermostat fan to On and close any fresh-air intake.
3. Run a portable HEPA air cleaner in each occupied room, starting with bedrooms.
4. Keep smoke out of the house: shut windows and skip candles, frying, vacuuming and smoking.
Filterbuy's 10-minute prep before July: write down your filter size, keep a spare MERV 13, pick your clean room and check that your HEPA cleaner's CADR fits it.
No Ductwork? How to Filter the Air in a Hillsboro Apartment
Without ducts, there's no furnace filter to upgrade. In apartments and homes heated by baseboards or ductless heat pumps, a portable HEPA air cleaner is the primary defense on smoke days, so set up one bedroom as a clean room.
Size it with EPA's rule: a smoke CADR of at least two-thirds of the room's square footage, so a 300-square-foot bedroom needs about 200. Pick one that produces no ozone. On a tight budget, EPA research found a box fan with a MERV 13 filter cuts smoke; use a certified fan from 2012 or newer and don't leave children alone with it. It's a stopgap, not a certified cleaner. Washington County maps clean air centers, and some Oregon Health Plan members who meet health and living-situation rules can get an air filter or air conditioner through OHA's climate supports benefit.
Which Filter Fits Hillsboro's AQI Readings
EPA recommends a MERV 13 or higher filter during smoky periods and says most furnaces and HVAC systems can use one if it is replaced often. Filterbuy's standing rule: have MERV 13 in place by the time the map hits 100. Confirm your filter size and check your HVAC manual first.
Matching Your Filter to Hillsboro's AQI
| Map reading | Likely cause | Filter move |
|---|---|---|
| 0–50 | Clean air | MERV 8 for everyday dust and pollen. |
| 51–99 | Dust or rising ozone | MERV 8 or 11; stock MERV 13 before smoke season. |
| 100+ (PM2.5) | Wood or wildfire smoke | MERV 13, fan On, HEPA per room, windows shut. |
| 100+ (ozone) | Hot-afternoon smog | No filter change; shut windows, exercise early. |
Check your HVAC manual first.
During smoke, check the filter often and replace it once it looks dark brown or black, which can be well before the usual interval. Filterbuy makes filters in the USA in more than 600 sizes, with fast and free 2-day delivery to most US states. Shop MERV 8, MERV 11 or MERV 13 air filters, compare them in our MERV rating guide, or set up auto-delivery.
Hillsboro Has Two Air Problems With Two Different Fixes
We make filters for a living, yet our Hillsboro advice starts with when not to buy one. Ozone days are a timing problem: the gas breaks down indoors, so a closed house and a morning workout handle most of it. Smoke days are a filtration problem, because the particles drift inside and stay until something removes them.
Filterbuy founder and CEO David Heacock says, "People buy one purifier for a three-bedroom house and assume they are covered. The filter already in the furnace treats every room, and moving the thermostat fan to ON costs nothing." Our air purifier vs. HVAC filter guide covers the trade-offs.
Supporting Statistics
1. 29 smoke days since 2013. Portland days at AQI 101 or higher from wildfire smoke, 2013 to 2025. Source: Oregon DEQ
2. 2.7 unhealthy ozone days a year. Clackamas County, the metro's worst for ozone, 2022 to 2024. Source: American Lung Association
3. 99 percent less airborne lead since 1980. Leaded-fuel piston aircraft are now the largest remaining source. Source: U.S. EPA
Frequently Asked Questions About Hillsboro Air Quality
What is the air quality in Hillsboro today?
The live map above shows Hillsboro's current AQI, color and leading pollutant. Above 100, sensitive groups should ease off.
Is the air quality bad in Hillsboro today?
Check the map's color. Orange (101 to 150) is unhealthy for sensitive groups; red (151 to 200) is unhealthy for everyone. A PM2.5 label usually means smoke.
What MERV rating do I need for wildfire smoke in Hillsboro?
MERV 13. Filterbuy recommends having it in place once the map reaches 100, with the thermostat fan On and a HEPA cleaner in each occupied room. Confirm your size and HVAC manual first.
Can I use my fireplace in Hillsboro today?
Between November 1 and March 1, check Washington County's air pollution page or call 503-846-8744. On a red day, fireplaces and wood stoves are off limits unless your household is exempt.
Does a furnace filter remove ozone?
No. HVAC filters, including Filterbuy's MERV 13, capture particles, not ozone gas. Indoor ozone usually runs lower with windows closed; limit afternoon outdoor effort.
Glossary
Air Quality Index (AQI): EPA's 0 to 500 air quality scale with six color-coded categories.
PM2.5: Particles 2.5 micrometers or smaller; 35.4 µg/m³ over 24 hours equals AQI 100.
Ground-level ozone: Smog that forms when emissions react with heat and sunlight.
NowCast: EPA's weighting of recent hourly data; it can lag sudden changes.
Hare Field monitor: Oregon DEQ's PM2.5 monitor at 1151 NE Grant Street, Hillsboro.
Red day: A November-to-March Washington County alert banning most wood burning.
Oregon DEQ: Oregon Department of Environmental Quality, the state air regulator.
MERV: Minimum Efficiency Reporting Value, a 1 to 16 filter rating.
HEPA: High-efficiency particulate air filtration in portable cleaners.
CADR: Clean air delivery rate, a portable cleaner's filtered airflow.
Filterbuy: U.S. maker of HVAC air filters in 600-plus sizes.