Cambridge, ON Live Wildfire Smoke Map
Get Alerts For Wildfires In Your Area
The moment a wildfire starts near you, you'll get an instant alert and simple tips to reduce your smoke exposure.
What's In The Smoke
30xSmaller than a human hair
Fine enough to reach deep into the lungs. A MERV 13 is built to capture it.
How Far It Travels
It Doesn't Stay Local
Smoke rides the wind far downwind — you can get smoky air with no fire nearby.
What To Do During A Smoke Event
Simple steps to reduce indoor exposure.
- Stay In, Close UpShut windows and doors to keep smoke out.
- Set Fan To "On"Keeps air cycling through your filter, not just when heating or cooling.
- Recirculate AirSwitch off fresh-air intake so you're not pulling smoke in.
- Run A MERV 13Built to capture the fine PM2.5 in smoke.
- Add A PurifierExtra filtration for the room you use most.
- Wear an N95 if OutsideFits snug to block fine particles — a cloth mask won't.
The Best Air Filter For Wildfire Smoke
During smoke events, the EPA recommends upgrading to a MERV 13 filter — or the highest-rated filter your system can handle — to help reduce the fine particles smoke brings indoors. MERV 13 is the level most home HVAC systems can run while still capturing PM2.5, the fine particulate that makes up the bulk of wildfire smoke.
- Captures PM2.5 particles
- Blocks ash, soot, and smoke odor
- Keeps your indoor air safe—even when the outdoor air is dangerous
- Meets the EPA's recommended rating for filtering fine wildfire smoke particles.
Wildfire Smoke FAQs
Facts About Wildfires
Over 70,000 wildfires burn in the U.S. every year.
Wildfire smoke can travel 1,000+ miles, affecting states that aren't even near the blaze.
Exposure to wildfire smoke can worsen asthma, trigger heart issues, and lead to ER visits.
Indoor air can hold more fine particles during wildfire events unless it's properly filtered.
The EPA advises using MERV 13 filters or portable HEPA air cleaners during wildfire smoke events.
Don't Wait Until The Smoke's Inside.
Use the live wildfire smoke tracker and upgrade your air filters today to protect your lungs and your home.
Shop Filters For Smoke Protection
Live Cambridge, ON Forest Wildfire & Smoke Map Today
Local Air Quality Tracking & Indoor Protection Solutions
The live wildfire and smoke map directly above this article is the place to start. It shows active fires, new fires from the past 24 hours and the smoke satellites can see around Cambridge, Ontario today. Having worked through every official source that covers the city, Filterbuy Canada reads Cambridge as a smoke city, not a fire city: smoke here nearly always drifts in from fires hundreds of kilometres away. Use the map to see where it is and the Kitchener Air Quality Health Index to see what is in the air right now.
TL;DR
Forest fires rarely come near Cambridge, but wildfire smoke does. The Filterbuy Canada live map above shows fires and smoke, Environment and Climate Change Canada's FireWork forecast shows where the smoke is heading, and the Kitchener AQHI shows what you're breathing. On smoky days, close the windows, set the furnace fan to "On" and switch to a MERV 13 furnace filter.
Key Takeaways
Cambridge has no provincial air monitoring station. Its official AQHI comes from the Kitchener station, 13.5 km from the Preston core and 18.1 km from Cambridge City Hall.
Environment and Climate Change Canada (ECCC) alerts name Cambridge, even though the reading comes from Kitchener.
In July 2026, smoke from northwestern Ontario wildfires roughly 1,070 km away brought an orange-level warning, and Cambridge closed its outdoor pools.
Health Canada guidance recommends a MERV 13 or higher filter for wildfire smoke.
Where Can I See a Live Fire and Smoke Map for Cambridge, ON Today?
Right here. The Filterbuy Canada live map at the top of this page shows active wildfires, new detections from the past 24 hours and satellite-spotted smoke, using fire data from Natural Resources Canada's Canadian Wildland Fire Information System (CWFIS) and smoke analysis from the U.S. National Oceanic and Atmospheric Administration (NOAA). Pair it with these official sources:
Why Can the Map Show Smoke When the AQHI Is Low?
Satellites see smoke from above, so they can't tell whether it's kilometres overhead or at street level. During the July 2026 Ontario smoke, NASA reported that air quality barely changed where the smoke stayed high and got worse where it sank. Filterbuy Canada treats the smoke layer as an early warning and the Kitchener AQHI as the verdict.
Is There a Forest Fire Near Cambridge Right Now?
Almost certainly not. Cambridge lies well south of Ontario's fire region, the area north of the French and Mattawa rivers where the province manages wildland fires, so the smoke here comes from fires in northern Ontario, Quebec and the Prairies. A grass, brush or building fire in the city is a 911 call for the Cambridge Fire Department, and any open-air fire needs Fire Chief approval under By-law 313-86.
This year's numbers explain the extra smoke. As of 24 September 2026, Ontario had recorded 789 wildland fires in its fire region, compared with 558 in 2025 and a 10-year average of 689.
Why Does Cambridge's Smoke Reading Come From Kitchener?
Because Cambridge has no station in Ontario's provincial network. Air Quality Ontario lists stations in Kitchener, Guelph and Brantford but none in Cambridge, and ECCC publishes the AQHI for this area under the name Kitchener. The number most apps show for Cambridge is really a Kitchener reading.
At Filterbuy Canada, we measured the gap ourselves by plotting Air Quality Ontario's station coordinates against Galt, Preston and Hespeler. The Kitchener station sits about 18.1 km from Cambridge City Hall and 13.5 km from the Preston core. Hespeler is the exception: it sits 13.8 km from the Guelph station and 15.7 km from Kitchener.
Alerts work differently: an ECCC warning for the Kitchener - Cambridge - Region of Waterloo region tells you Cambridge is affected, and the Kitchener AQHI tells you how heavy the smoke is. Even Region of Waterloo Public Health's link to check the local AQHI opened the Kitchener page when we followed it.
What Did a Wildfire Smoke Week Look Like in Cambridge?
July 2026 is the clearest recent example, pieced together from City of Cambridge notices and ECCC warnings. Smoke from northwestern Ontario wildfires, including the Thunder Bay 36 fire in Wabakimi Provincial Park, reached Waterloo Region, and within a day city services began to change.
What stayed with us was the distance: by Filterbuy Canada's straight-line calculation, Thunder Bay 36 burned about 1,070 km northwest of Cambridge City Hall, yet the city still closed its outdoor pools.
"The fire is usually hundreds of kilometres away and the nearest monitor sits in another city. On a hazy day, the one thing a Cambridge household fully controls is the filter already in its furnace."
— Filterbuy Canada Indoor Air Quality Team
What Do AQHI Numbers Mean During a Smoke Event?
The Air Quality Health Index (AQHI) is Canada's official health-risk scale for air quality, running from 1 to 10+. During wildfire smoke, ECCC calculates the hourly AQHI from fine particulate matter (PM2.5) alone, so the number tracks the smoke closely. Forecasts are issued at 6:00 a.m. and 5:00 p.m., so a morning check covers the day.
1 to 3, low risk: enjoy usual outdoor activities.
4 to 6, moderate risk: people at risk should consider reducing strenuous outdoor activity if they have symptoms.
7 to 10, high risk: people at risk should reduce or reschedule strenuous outdoor activity.
10+, very high risk: people at risk should avoid it, and everyone should reduce or reschedule it.
People at risk include children, adults over 65 and people with health conditions. Region of Waterloo Public Health notes that air can be poor even when you can't see or smell smoke. Many apps show the U.S. Air Quality Index (AQI) instead, a 0 to 500 scale on which readings above 100 are unhealthy for sensitive groups.
How Do I Protect My Indoor Air in Cambridge During Wildfire Smoke?
Follow ECCC alerts and Region of Waterloo Public Health first, then filter whatever gets in. Health Canada advises keeping windows and doors closed and setting your system to recirculate, and its cleaner air spaces guidance recommends a MERV 13 or higher filter for fine smoke particles.
Put a MERV 13 in the furnace. The U.S. EPA notes that most furnaces can take one without equipment problems when the filter is changed often. Check that it fits the slot snugly.
Set the furnace fan to "On." On "Auto," filtering stops between heating or cooling cycles.
Run a portable HEPA air cleaner in each room people use, bedrooms first. Health Canada recommends a smoke CADR of at least two-thirds of the room's area in square feet, so a 3 m by 3.7 m bedroom (120 sq. ft.) needs 80 or more. Skip ozone-producing devices.
Close the house up. Limit exhaust fans, follow your HRV or ERV manufacturer's smoke-day instructions, and avoid candles, incense, wood stoves, frying, smoking and vacuuming without a HEPA vacuum.
Put heat first. Health Canada says to prioritize keeping cool when heat and smoke coincide, so run the air conditioning or visit a Region of Waterloo cooling and clean air space.
Check the filter during a smoke event. The EPA advises replacing it once it looks dirty, dark brown or black, which can be well before the usual interval. Keep a spare on hand.
No furnace or ductwork? Portable HEPA air cleaners become your main defence, so start with the room you sleep in.
Our rule of thumb at Filterbuy Canada is to act early: once the Kitchener AQHI reaches 7, or the U.S. AQI reaches 100, put a MERV 13 filter in the furnace, set the fan to "On" and run a portable HEPA air cleaner in each occupied room. Our MERV 13 vs. HEPA guide explains both layers.
Supporting Statistics: What U.S. Research Shows
1. Asthma Emergency Visits Rose 17% During Canadian Smoke
On 19 days of 2023 Canadian wildfire smoke (AQI 101 or higher), U.S. emergency visits for asthma ran 17% above expected. Source: CDC MMWR, 2023.
2. Wildfire PM2.5 Hits Harder Than Other PM2.5
Each 10 micrograms per cubic metre of wildfire PM2.5 raised respiratory hospitalizations 1.3% to 10%, versus 0.67% to 1.3% for other PM2.5. Source: Aguilera et al., 2021, NOAA repository.
3. About 90% of Our Time Is Spent Indoors
Americans spend about 90% of their time indoors, and the EPA counts wildfire smoke among the outdoor pollutants that get inside. Source: U.S. EPA.
Frequently Asked Questions
Is there a wildfire in Cambridge, Ontario today?
Very unlikely. Cambridge lies outside Ontario's fire region, and the live map at the top of this page shows any active wildfires. If you see or smell a fire in the city, call 911.
Why is it smoky in Cambridge today?
Almost always because of distant wildfires. The smoke layer on the live map above shows where it is, FireWork shows where it is heading and the Kitchener AQHI shows how much is in the air.
Is it safe to go outside in Cambridge today?
Check the Kitchener AQHI. At 1 to 3, carry on as usual. Readings of 4 to 6 mean people at risk should ease off if they have symptoms, and at 7 or higher they should reduce or reschedule strenuous activity.
Where is the air quality monitor for Cambridge?
There isn't one in Cambridge. The official AQHI comes from the Kitchener station, although Hespeler sits slightly closer to the Guelph station.
What MERV rating is best for wildfire smoke?
MERV 13. Health Canada guidance recommends it for smoke, and the U.S. EPA notes most furnaces can take it when it is changed often. Filterbuy Canada carries MERV 13 (Optimal) in more than 600 sizes.
Glossary
AQHI (Air Quality Health Index): Canada's 1 to 10+ health-risk scale for air quality, calculated from PM2.5 alone during wildfire smoke.
AQI (Air Quality Index): The U.S. EPA scale from 0 to 500 shown by many apps.
PM2.5: Fine particles 2.5 micrometres across or smaller, the main pollutant in wildfire smoke.
MERV (Minimum Efficiency Reporting Value): An ASHRAE filter rating; higher numbers capture smaller particles. Filterbuy Canada labels MERV 8, 11 and 13 as Standard, Superior and Optimal.
HVAC: Heating, ventilation and air conditioning, the system that moves household air through the furnace filter.
CADR (clean air delivery rate): How much filtered air a portable air cleaner delivers; use the smoke rating for wildfire smoke.
Get Ready for the Next Smoke Season
Filterbuy Canada carries pleated air filters in more than 600 sizes, including custom, with free shipping to Canada on every order and prices in CAD. Choose MERV 13 (Optimal) in your size before smoke season, or Subscribe and Save so fresh filters arrive on a schedule you can edit, skip or cancel anytime. See the live Ontario air quality map for provincial readings. Questions? Call (855) 345-8289 or email info@filterbuy.com.