TL;DR

London, Ontario, Canada rarely has local forest fires, but smoke from distant wildfires regularly drifts over the city between spring and fall. Check the live map below for fires and smoke near London, ON today, then check the Air Quality Health Index (AQHI). When smoke arrives, follow official alerts first. Filterbuy's advice as a filter maker is to close up the house, put a MERV 13 filter in your furnace, set the fan to ON, and run a portable HEPA air cleaner in each occupied room.

Key Takeaways

• Wildfire smoke in London, ON almost always comes from fires hundreds of kilometres away, usually in northwestern Ontario or Quebec.

• In July 2026, smoke from northwestern Ontario pushed London's AQHI to 10+. The event lasted about five days from the first warning to low risk.

• Health Canada recommends HVAC filters rated MERV 13 or higher for smoke. Filterbuy's action line is an AQHI of 7.

Live Wildfire and Smoke Map for London, Ontario Today

The live map below shows active wildfire hotspots and forecast smoke plumes around London, ON and Middlesex County. Maps show where the smoke is, so Filterbuy built the rest of this page around what to do at home.

Use the standard Filterbuy.ca fire-smoke map module already live on the Ontario wildfire and smoke map page (fire layer: CWFIS/Natural Resources Canada; smoke layer: NOAA/NESDIS HMS; wildfire alert sign-up by postal code). Centre it on London, ON (42.98° N, 81.25° W) and keep the conditions block below as server-rendered text.

London, ON Wildfire and Smoke Conditions as of September 24, 2026

Ontario's September 23, 2026 forest fire update listed 27 active fires in the Northwest Region. So far, the province has logged 789 wildland fires this year against a 10-year average of 688, and the fire season runs until October 31.

Where Does Wildfire Smoke in London, ON Come From?

London's wildfire smoke comes from large forest fires far to the north. Northwest winds carry plumes south from boreal fires in northwestern Ontario or Quebec, and Health Canada notes smoke can travel thousands of kilometres. That is why London can get smoke warnings with no fire nearby.

Filterbuy's air quality team followed July 2026 closely, and it showed how quickly London's air can change. Environment and Climate Change Canada (ECCC) issued a yellow Air Quality Warning for London and Middlesex County on July 15 and later upgraded it to orange. Two days later, London's AQHI had reached 10+, according to Dr. Alex Summers, medical officer of health for the Middlesex-London Health Unit. The City of London closed outdoor recreation facilities. With so little warning, a fresh filter should go in before the forecast turns.

Ontario's 2026 fire season became the largest on record by area burned, passing 7,250 square kilometres by July 21, according to The Canadian Press via Global News.

Is There a Forest Fire in London, ON?

Rarely. Most fires in the city are grass or brush fires, and the London Fire Department handles them. If you see flames or heavy smoke nearby, call 911; Ontario asks everyone south of the French and Mattawa rivers to report fires that way.

How Do You Read the London, ON Smoke Map and AQHI?

The Air Quality Health Index (AQHI) rates risk as low from 1 to 3, moderate from 4 to 6, high from 7 to 10, and very high above 10. During wildfire smoke events, ECCC recalculates it every hour using only PM2.5, the tiny particles in smoke, so London's AQHI reading can climb fast.

Many U.S. apps show the Air Quality Index (AQI) instead, a different 0-to-500 scale. Filterbuy's action line is an AQHI of 7, where ECCC's high-risk band begins. From that point we recommend MERV 13 in the furnace, the fan set to ON, and a portable HEPA cleaner in each occupied room, bedrooms first.

The London Smoke Action Guide (Filterbuy framework, reviewed by David Clark)