Wildfire Smoke & Air Quality
A plain-language overview of the wildfire smoke affecting Southeast Michigan — what's happening, why it matters, how to read the air quality numbers, and how to keep yourself and your neighbors safe.
What's Happening
If the sky has looked hazy, the sun has turned orange, and you can actually taste and smell something in the air — this isn't ordinary fog or summer haze. Smoke from large wildfires burning in Canada has drifted south and settled across our region. What we're breathing right now is a genuine, large-scale air quality event, not just a change in the weather.
Wildfire smoke is made up of tiny airborne particles and gases. Even far from the fires, that smoke can reduce visibility, irritate the eyes and throat, make breathing harder, and leave many people feeling tired, headachy, or simply “off.” When conditions get bad enough, spending time outdoors — or working, exercising, or traveling in it — can genuinely be unsafe.
An event like this touches nearly everything: how well we breathe, how far we can see on the road, whether it's wise to be active outside, how we get to work, and how our most vulnerable neighbors are holding up. It reaches across the whole region at once, so it's worth understanding what's happening and what we can do about it.
Who Is Most At Risk
Smoke doesn't affect everyone the same way. What's a mild annoyance for one person can be a serious health problem for someone else. Pay especially close attention to:
- People with asthma, COPD, or other lung conditions
- People with heart disease
- People who are pregnant
- Young children, whose lungs are still developing
- Older adults
- Anyone doing heavy outdoor work or exercise
Making Sense of the Air Quality Numbers
You'll hear a lot of terms during a smoke event. Here's what they actually mean, in plain language.
AQI — Air Quality Index
A simple 0–500 scale that turns complicated pollution measurements into a single, easy-to-read number with a color. The higher the number, the more polluted the air and the greater the health concern — think of it as a “how safe is the air right now?” score.
PM2.5 — Fine Particles
“PM” means particulate matter — tiny particles floating in the air. PM2.5 are 2.5 microns wide or smaller, roughly 30 times thinner than a human hair. They slip deep into the lungs and even the bloodstream. Wildfire smoke is loaded with PM2.5.
PM10 — Coarse Particles
Larger particles up to 10 microns wide — dust, pollen, and mold. Your nose and throat catch more of these before they reach deep into the lungs. PM10 still matters, but it's usually a bigger factor with dust and pollen than with smoke.
AQI vs. Raw Particle Levels
Raw particle concentration is the actual measured amount of particles in the air (in micrograms per cubic meter). The AQI translates that raw measurement into the friendly 0–500 health scale. The raw number is the science; the AQI is the plain-English interpretation of it.
Why PM2.5 Is the Big Concern With Smoke
Wildfire smoke is dominated by PM2.5. Because these particles are so small, your nose and throat can't filter them out — they travel deep into the lungs and can trigger coughing, tightness, aggravated asthma, and strain on the heart. During a smoke event, PM2.5 is usually the number that matters most.
What “Hazardous” really means: when the AQI reaches the Hazardous range, the air is unhealthy for everyone, not just sensitive groups. In practical terms, that's the point to treat outdoor air as something to avoid: stay inside, keep exertion low, and take any breathing symptoms seriously.
AQI Categories at a Glance
| AQI Range | Category | What It Means | What To Do |
|---|---|---|---|
| 0–50 | Good | Air quality is clean and poses little or no risk. | Enjoy normal outdoor activities. |
| 51–100 | Moderate | Acceptable, but unusually sensitive people may notice mild effects. | Most people are fine; the very sensitive can take it easier outdoors. |
| 101–150 | Unhealthy for Sensitive Groups | People with lung/heart conditions, children, and older adults may feel effects. | Sensitive groups should limit prolonged or heavy outdoor exertion. |
| 151–200 | Unhealthy | Everyone may begin to feel effects; sensitive groups more seriously. | Cut back on outdoor exertion; sensitive groups should stay indoors. |
| 201–300 | Very Unhealthy | Health warnings; the risk is significant for the whole population. | Avoid outdoor activity; stay inside with clean, filtered air. |
| 301+ | Hazardous | Emergency conditions; everyone is likely to be affected. | Stay indoors, keep exertion minimal, and use a real respirator if you must go out. |
Getting Through a Smoke Event Safely
At Home & Indoors
- Stay indoors as much as possible while levels are high.
- Keep windows and doors closed to keep smoke out.
- Run central air conditioning on recirculate so you're not pulling in outside air.
- If your HVAC system supports it, use a higher-efficiency filter — the EPA recommends MERV-13 (or the highest rating your system can handle). On the older residential rating scale, that's roughly a Filtrete 1900 (MPR) or FPR 10 filter.
- Use a portable air cleaner with a HEPA filter if you have one, especially in the room where you spend the most time.
If You Must Go Out
- Limit time outdoors and avoid heavy exertion like running, yard work, or hard labor.
- If you must be outside for a while, wear a properly fitted NIOSH-approved N95 or P100 respirator that seals against your face.
- Keep car windows up and set ventilation to recirculate while driving.
- Take breathing symptoms seriously — don't push through shortness of breath, chest tightness, or dizziness.
EPA Guidance: Choosing the Right Filter
To clean smoke particles out of your indoor air, the EPA recommends using the highest-efficiency filter your heating and cooling system can handle — ideally MERV-13. Manufacturers label filters on a few different scales, so here's how they line up:
- MERV-13 — the standard industry rating; MERV-13 or higher captures fine smoke particles well.
- Filtrete MPR 1900 — 3M's rating scale; MPR 1500–1900 is roughly equivalent to MERV-13.
- FPR 10 — the Home Depot rating scale; FPR 10 is roughly equivalent to MERV-13.
Check that your furnace or air handler can actually accommodate a MERV-13 filter without restricting airflow — if not, use the highest rating it supports and run the system's fan continuously so air keeps passing through the filter.
Don't have a good filter or a HEPA cleaner? The EPA notes you can build a temporary DIY air cleaner by attaching a MERV-13 furnace filter to a box fan (or, better, several filters in a “Corsi–Rosenthal box”). It's an inexpensive way to noticeably lower smoke particles in a single room.
EPA — Wildfires and Indoor Air Quality • EPA — DIY Air Cleaner Guidance
What Does Not Protect You
Wildfire smoke particles are extremely small, and everyday face coverings simply can't filter them out. The following do not provide meaningful protection from smoke:
- A wet rag or damp cloth held over the face
- A bandana or scarf
- A surgical or “procedure” mask
- Loosely covering your nose and mouth
These may block large dust, but they leave big gaps and don't stop fine PM2.5 particles. Only a properly fitted N95 or P100 respirator that seals to your face offers real protection.
Check Current Conditions
When smoke is in the area, one of the best tools to bookmark is the AirNow Fire and Smoke Map. It brings together official monitors, low-cost community sensors, fire locations, and smoke plume information all on one map.
It's useful because it shows conditions right where you are — not just a regional average — along with where the smoke is coming from and how it may move. Check it before deciding whether to head outside, run errands, or keep the kids in for the day.
Open the AirNow Fire and Smoke MapOutlook, Updates & Forecasts
How long the smoke sticks around depends on two things: how the fires in Canada behave, and what our own weather does. The smoke gets pushed here by upper-level winds, and it tends to clear when the wind shifts to a cleaner direction or when a good soaking rain scrubs the particles out of the air. Watching the fire reports up north alongside our local wind and precipitation forecast gives the best picture of when improvement is likely.
Canada — Fire & Smoke Reports
Official Canadian sources on how extensive the fires are and where the smoke is heading.
- Canadian Interagency Forest Fire Centre (CIFFC) National daily situation report on active fires across Canada.
- Canadian Wildland Fire Information System Fire maps, danger ratings, and active-fire extent across the country.
- FireSmoke Canada — Smoke Forecast Animated forecast of where the smoke plume is expected to travel next.
- Environment Canada — Air Quality & Smoke Canada's official air quality and wildfire smoke outlook.
Michigan — Weather & Wind Outlook
Watch for rain and wind shifts here at home — they're what actually clear the air locally.
- National Weather Service — Detroit/Pontiac Local forecast, hazards, and any air quality alerts for Southeast Michigan.
- AirNow — Michigan Air Quality Forecast Today's and tomorrow's forecast AQI for Michigan communities.
- Michigan EGLE — Air Quality & Advisories State air monitoring and any active Air Quality Advisories.
- NWS Weather Prediction Center Multi-day rain and frontal outlook — when a wind shift or rain may arrive.
Helpful Reference Links
- AirNow Fire and Smoke Map Live smoke, fires, and local sensor readings — your primary go-to tool.
- AirNow — Understanding the AQI Plain-language basics on what the Air Quality Index means.
- AirNow Home — Current Conditions Look up current air quality by ZIP code or city.
- EPA — Wildfires and Indoor Air Quality How to keep the air inside your home cleaner during a smoke event.
- EPA — DIY Air Cleaners & HVAC Filters Filter ratings (MERV-13) and how to build a low-cost box-fan air cleaner.
- CDC — Staying Safe During Wildfire Smoke Health guidance and safety steps for wildfire smoke conditions.
- AirNow Mobile App Check air quality on the go and get alerts for your area.
Looking Out for One Another
A regional smoke event is more than a weather headline — it's a health and quality-of-life event that touches everyone in the area, from how we breathe to how we work, travel, and rest. That's exactly why awareness matters, and why a quick check-in is worth the effort. A short phone call, a knock on a door, or a friendly word can help someone who might be struggling quietly. Stay informed, take care of yourself, and take a moment to look out for the people around you — that's what this group does best.