Ann Arbor 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 Ann Arbor Air Today?
What High AQI Means for Your Lungs in Ann Arbor
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 Ann Arbor, MI Now
TL;DR
The live map on this page shows Ann Arbor’s real-time air quality from EPA AirNow monitors. Readings from 0 to 50 are Good. Above 100, sensitive groups should follow their doctor’s plan and official guidance. Fine particles (PM2.5), specks about 1/30th the width of a hair, and summer ozone cause most daily swings, while Canadian wildfire smoke now drives the worst days. Filterbuy, a U.S. filter maker since 2013, covers what to do indoors.
Reading the Live Ann Arbor AQI Map Before You Head Out
Filterbuy builds live AQI pages nationwide and reads every one the same way: color first, then pollutant. The color tells you how to plan your day; the pollutant tells you how to respond.
Key Takeaways
Fine particulate (PM2.5) and ground-level ozone drive most Ann Arbor AQI changes.
On July 16, 2026, Canadian wildfire smoke pushed the Ann Arbor area’s AQI to about 405, in the Hazardous range.
Filterbuy’s action line is AQI 100: MERV 13 in the HVAC, fan On, a HEPA cleaner in each occupied room, house closed.
Ann Arbor AQI Categories and the Action Each One Calls For
The U.S. AQI runs from 0 to 500 and splits into six color-coded categories. The categories, ranges and colors come from EPA AirNow. The “What to Do” column is Filterbuy’s guidance.
Always act on the category the live map is showing now.
When Ann Arbor’s AQI Seems Out of Step With the Sky
Hazy sky but a yellow reading? The AQI is a NowCast, a rolling average that can lag behind a fast-moving plume. The nearest federal monitor also sits miles east in Ypsilanti.
When sources disagree, Filterbuy checks them in this order:
The live map above for the official category.
The city’s sensor map for your side of the Huron River.
The AirNow Fire and Smoke Map for plumes moving faster than the NowCast.
Your nose. If you smell smoke indoors, act on the higher reading.
Can You Safely Breathe Ann Arbor’s Air Today?
Below 50, the air is fine for everyone. From 101, AirNow flags sensitive groups: people with asthma, COPD or heart disease, children and adults over 65. If that includes you, follow your doctor’s plan and official guidance. Above 150, everyone should cut back outdoors.
Checking Ann Arbor’s Air Quality Forecast Ahead of Time
EGLE posts Ann Arbor’s next-day forecast on MiAir and AirNow. Free EnviroFlash alerts send it by email.
Filterbuy plans filter changes around Ann Arbor’s seasons:
Patterns, not forecasts; act on the live map.
On hot, still days, the Southeast Michigan Council of Governments (SEMCOG) may declare an Ozone Action Day. Run the Huron River trails early that day. Smoke doesn’t follow that calendar.
Ann Arbor Air Quality Neighborhood by Neighborhood
Since September 2025, 10 city sensors measuring PM2.5, nitrogen dioxide and ozone have posted readings on the city’s public sensor map. Sean Reynolds of the city’s Office of Sustainability and Innovations has noted that sensors south of the Huron River sometimes read worse than those north of it.
Local influences by area. For current readings, use the live map above.
What’s in Ann Arbor’s Air? PM2.5, Ozone and More
On most days, either PM2.5 or ground-level ozone sets Ann Arbor’s AQI. Ozone forms as sunlight cooks the region’s vehicle and industrial emissions. In May 2023, EPA redesignated Washtenaw County and the rest of Southeast Michigan as meeting the 2015 ozone standard.
Ozone breaks down quickly indoors, so closing the windows does much of the work. PM2.5 doesn’t. The particles slip in around doors and windows and stay airborne for hours. Removing them takes filtration, which is where your MERV rating matters.
How Ann Arbor’s Air Stacks Up Against Other Metros
The American Lung Association’s State of the Air 2026 ranked the Detroit-Warren-Ann Arbor metro 9th worst in the U.S. for year-round particle pollution and 39th for ozone. Those rankings reflect Wayne County, not Washtenaw (its report card). Compare nearby cities on our Michigan air quality map and Detroit live AQI map.
Wildfire Smoke in Ann Arbor: What July 2026 Taught Us
On the morning of July 16, 2026, Washtenaw County put the area’s AQI at about 405, well into the Hazardous range. The same day, EGLE upgraded its alert for all of Michigan to Hazardous.
Michigan households tend to reach Filterbuy right after a smoke event, not before. That timing is backward.
When smoke moves in, check EGLE’s MiAir site and AirNow first and follow any official instructions. At AQI 100, Filterbuy’s action line, we recommend four steps in this order:
MERV 13 in the HVAC. It’s the whole-home layer; the central system moves far more air than a portable unit.
Thermostat fan to On. Auto filters only while heating or cooling; On filters continuously.
A portable HEPA air cleaner in each occupied room, bedrooms first. Size it so its smoke CADR is at least two-thirds of the room’s square footage, the rule from EPA’s ENERGY STAR program. A 300 sq ft bedroom needs a smoke CADR of about 200. Skip cleaners that produce ozone.
Close the house up. Shut windows and doors, and skip candles, frying, smoking and vacuuming without a sealed unit.
During the event, check the filter often and replace it when it looks dark brown or black, which can be well before the normal interval. Keep a spare on hand. Pleated filters capture particles, not odors; for lingering smell, see our Odor Eliminator line.
Follow plumes on our live Michigan wildfire and smoke map, get ready with our wildfire season checklist, and see the state health department’s MDHHS guidance on wildfire smoke.
Air Quality Advisory or Alert: What EGLE’s Notices Mean for Your Ann Arbor Day
EGLE issues two levels of notice:
Air Quality Advisory: two or more monitors are expected to reach Unhealthy for Sensitive Groups (orange).
Air Quality Alert: two or more monitors are expected to reach Unhealthy or worse (red, purple or maroon).
Sensitive groups should adjust plans for an advisory; everyone should limit exertion during an alert.
No Ducts? Protecting Air in Older Ann Arbor Homes and Rentals
Many houses on the Old West Side and around Burns Park were built before central air, and many campus-area rentals run on radiators. No ducts means no filter slot. If you live in one, the MERV advice on this page won’t apply, and we’d rather tell you that than sell you a filter that won’t fit. Portable HEPA air cleaners are your primary defense, not an add-on:
One in each occupied room, sized with the CADR rule above.
Windows shut during smoke, with any window AC set to recirculate.
A plan for heat: if it’s too hot to stay sealed up, use one of Washtenaw County’s cooling and refuge sites.
Filterbuy’s Read on Ann Arbor’s Numbers
Filterbuy has built pleated filters in the U.S. since 2013 for more than two million households, and two things stand out in Ann Arbor’s data:
Ann Arbor’s worst air day is now a smoke day. In 2026, smoke pushed the AQI past 400.
July is the month to plan around. The 2026 smoke hit during Art Fair week; a filter ordered that morning arrives after the smoke.
Checking a live map and having the right filter already installed makes the difference between reacting to smoke and staying ahead of it.
David Heacock, Founder and CEO, Filterbuy
Matching Your Filter to Ann Arbor’s AQI Level
At AQI 100 and above, Filterbuy recommends MERV 13 in the HVAC and a portable HEPA cleaner in each occupied room. That threshold is our call.
The EPA’s guidance is a filter rated MERV 13 or higher during smoke events. EPA also notes that most furnaces and HVAC systems can run MERV 13 without equipment problems when the filter is replaced often. Confirm the size and slot depth like any filter.
AQI 100 is Filterbuy's action line. EPA's orange category starts at 101.
Shop MERV 13 in your size, or MERV 8 and MERV 11 for everyday use.
Supporting Statistics for Ann Arbor Households
EPA: a MERV 13–16 filter can remove up to 95% of the particles passing through it.
Portable high-efficiency air cleaners: up to 85%.
Why it matters: use both layers.
1,327,043 Michigan children breathe unhealthy levels of air pollution.
Why it matters: children are a sensitive group, so watch orange days.
Source: American Lung Association, State of the Air 2026: Michigan
Michigan ranked sixth in the U.S. for current asthma: 10.9% (2016).
Why it matters: act at AQI 100.
Source: MDHHS Michigan Asthma Atlas
Frequently Asked Questions
What Is the Air Quality in Ann Arbor Today?
Filterbuy’s live AQI map at the top of this page shows Ann Arbor’s air quality today, including the driving pollutant.
Is the Air Quality Bad in Ann Arbor Today?
It depends on how high Ann Arbor’s air pollution reads today. At 100, start Filterbuy’s action list; above 150, everyone should cut back outdoors.
What MERV Rating Do I Need for Wildfire Smoke in Ann Arbor?
MERV 13. EPA recommends MERV 13 or higher during smoke events. Filterbuy’s line is to switch at AQI 100.
How Do I Protect My Home From Wildfire Smoke in Ann Arbor?
Check MiAir and AirNow first. At AQI 100, use MERV 13 with the fan On, a HEPA cleaner in each occupied room and a closed house.
Where Can I Check Ann Arbor PM2.5 Today by Neighborhood?
Use the city’s sensor map, which covers 10 locations.
Glossary
AQI (Air Quality Index): The EPA’s 0–500 daily air pollution scale.
PM2.5: Fine particles 2.5 micrometers or smaller, the main part of wildfire smoke.
Ozone (O3): A lung irritant formed when sunlight reacts with emissions.
NowCast: EPA’s rolling AQI average of up to 12 hours.
EGLE: Michigan Department of Environment, Great Lakes, and Energy.
MERV: Minimum Efficiency Reporting Value, a filter’s 1–16 particle-capture rating.
HEPA: High-Efficiency Particulate Air, the standard for portable air cleaners, not home HVAC systems.
CADR: Clean Air Delivery Rate, how much filtered air a portable cleaner delivers.