Smoke Is Now Part of a Saskatoon Summer
On 29 May 2025 the Government of Saskatchewan declared a provincial wildfire state of emergency. The next morning, smoke from fires in northern Saskatchewan and northern Alberta moved into Saskatoon. By early afternoon most of the province was under an air quality statement or warning, and Environment Canada's message was that during heavy smoke, everyone's health is at risk, whatever their age or health.
The number to watch is the Air Quality Health Index (AQHI), which Environment and Climate Change Canada publishes for Saskatoon on weather.gc.ca. It combines fine particles, ozone and nitrogen dioxide into one score:
| AQHI | Health risk |
|---|---|
| 1 to 3 | Low |
| 4 to 6 | Moderate |
| 7 to 10 | High |
| Above 10 | Very high |
The part of smoke that matters indoors is the fine particles (PM2.5). They're too small to see, they drift through gaps around windows and doors, and they settle on every surface in the house. That makes smoke a cleaning problem as well as an air problem, and the two have to be handled in the right order.
Keep It Out: Windows, Furnace and Filters
- Close windows and doors as much as possible while smoke is around. The exception is extreme heat: federal guidance puts staying cool first, because heat is its own danger.
- Set the furnace fan to recirculate, and use the best filter your system can take. Health Canada's 2020 guidance names MERV 13 or higher. Check your furnace manual first, since a denser filter restricts airflow on some systems. Switch back to fresh-air intake once the smoke has passed.
- Go easy on exhaust fans. Federal guidance says to limit them. Every cubic foot a bathroom fan or range hood pushes outside is replaced by outdoor air leaking in somewhere else.
- Keep indoor humidity between 35 and 50%, the range in the same Health Canada guidance. If you run a humidifier, our hard water guide explains why an ultrasonic one leaves white dust in Saskatoon.
Portable Air Cleaners: What Size Actually Helps
A portable air cleaner with a HEPA filter is the most direct way to pull fine smoke particles out of a room. Health Canada's sizing advice comes down to three rules:
- Look for AHAM certification (the Association of Home Appliance Manufacturers label). It lists the unit's clean air delivery rate (CADR) and the room size it's rated for.
- Tobacco smoke CADR of at least two-thirds of the room's floor area in square feet. For wildfire smoke, Health Canada says to buy the highest tobacco smoke CADR your budget allows, because both kinds of smoke are fine particles.
- Size up for tall ceilings. Ratings assume an 8-foot ceiling. A room with vaulted ceilings needs a unit rated for a bigger room.
Worked example: a 12 × 12 ft bedroom is 144 sq ft, so it needs a tobacco smoke CADR of at least 96. With an 8-foot ceiling that room holds 1,152 cubic feet of air. The 2020 guidance asks for filtered air equal to 2 to 3 times the room volume per hour, which works out to about 38 to 58 cubic feet per minute. The two-thirds rule already covers that with room to spare.
Run it on a higher fan speed with the door closed, and point it so it doesn't blow straight at anyone. A bedroom is the obvious room to protect, since that's where you spend eight hours breathing. Skip anything that makes ozone. Health Canada advises against ozone generators in homes, whatever they're sold as.
A do-it-yourself air cleaner (a box fan with a furnace filter attached) is supported by the evidence as a short-term emergency option, according to the federal guidance. It comes with conditions: a clean, newer (2012 or later) certified box fan with a safety fuse, filters changed regularly during smoke events, no extension cords, kept clear of walls and furniture, and never left running unattended or while you sleep.
What Not to Do Indoors While the Smoke Is Here
This is where normal cleaning habits work against you. Health Canada's list of indoor sources to cut during smoke events includes:
- Vacuuming without a HEPA filter. An ordinary vacuum sends the finest dust back into the air. The guidance says settled dust should be removed by wiping and wet mopping instead.
- Dry dusting, for the same reason. A damp microfibre cloth traps particles that a feather duster just moves around.
- Cleaning products that give off a lot of VOCs, meaning strong solvents and heavy fragrances. Our eco-friendly products guide covers low-odour options that still work.
- Candles and incense, smoking, and wood stoves. Each one adds more fine particles to air that's already carrying too many.
In practice, during a smoky week you keep the house tidy and hold the real cleaning until the air clears. Then you do it properly, once.
Once the Smoke Clears: The Cleanup
Federal guidance is simple on timing: once outdoor air quality improves, open the windows and wet-mop the floors. For the rest of the house, the Canadian Centre for Occupational Health and Safety (CCOHS) sets out cleaning methods for buildings that were exposed to smoke but not burned:
| Surface | Method |
|---|---|
| Walls and ceilings | Wet-wipe with a detergent and water mix |
| Hard floors | HEPA vacuum, or wet-wipe with detergent and water |
| Carpets | HEPA vacuum, or wet-wipe with detergent and water |
| Clothing, bedding, curtains | Machine-wash in hot water (check the care label) |
| Glass, ceramics, metal, hard plastic | Hot water and detergent |
| Furnace and ventilation filters | Replace or clean to the manufacturer's instructions |
| HVAC ducts, attics | Professionals, not a household job |
CCOHS also lists what not to do: no leaf blowers, no compressed air and no other tools that raise dust. And never mix cleaning chemicals. Where there's visible ash or soot, its advice for cleanup crews is an N95 respirator, gloves and eye protection.
Where smoke residue collects in a Saskatoon house
Smoke comes in wherever air leaks in, so that's where the film is heaviest. Work from the top of each room down, so whatever falls gets picked up by the floor pass at the end:
- Window sills and tracks. The grey grit in the track is the first place to look, and the same tracks already collect a summer of pollen and cottonwood fluff.
- Blinds, ceiling fan blades, the top of the fridge and door frames. These are the high flat surfaces that don't get touched in a normal week.
- Soft furnishings. Throws, cushion covers, curtains and bedding hold the smell. Washing them does more for a lingering odour than any spray.
- Entry floors and mats. HEPA vacuum first, then a damp mop.
- The furnace filter. A MERV 13 filter that spent a week catching smoke has done its job. Check it once the smoke passes rather than waiting for the usual date.
If a smoky smell hangs on after all that, don't be tempted by an ozone machine to "deodorize". The same Health Canada advice against ozone generators applies.
Who Should Take It Most Seriously
Federal health guidance names the people most at risk from smoke. They include people 65 and older, people with an existing illness or a chronic lung or heart condition, pregnant people, infants and young children, and anyone who works or exercises outdoors. For those households the advice is to reduce or reschedule strenuous outdoor activity and to get medical help if symptoms appear. In Saskatchewan, HealthLine 811 answers health questions around the clock.
A well-fitting NIOSH-certified N95 (or an equivalent KN95 or KF94) may reduce exposure outdoors. Federal guidance says masks aren't for children under two.
If you look after an older parent in Saskatoon, the cleanup is exactly the kind of work that shouldn't fall to them: reaching blinds, washing curtains, a full wet-dusting pass. Our senior home support covers light housekeeping and laundry, and a regular clean keeps the house on top of it through smoke season.
When to Hand It Off
A post-smoke clean is really a deep clean with stricter rules. It means every surface wet-wiped top to bottom, the window tracks, blinds and baseboards, and floors done with a HEPA vacuum and a damp mop. That's what we do. Duct cleaning, and fire or heavy soot restoration after a fire at the property itself, are specialist jobs. If your home was damaged by fire, call your insurer and a restoration company first. See our cost guide for typical deep clean prices.