Southern Ontario Faces Another Round of Wildfire Smoke and Unhealthy Air This Week
/Southern Ontario continues to deal with lingering wildfire smoke from fires burning across the Prairies and Northern Ontario. While the thickest smoke has cleared out of the region for now, Thursday and Friday brought some of the worst air quality readings we've seen since at least 2023, with several areas reaching unhealthy levels.
As of Sunday evening, there’s still some smoke in the atmosphere - mainly in the upper levels, but we are seeing minor surface-level impacts. This is resulting in reduced air quality in certain parts of the province, although it’s not nearly as bad as it was a few days ago.
SOURCE: AQICN.ORG
Air quality readings are sitting above 100 in parts of Southwestern Ontario, the Golden Horseshoe, and sections of Northern Ontario. That level falls into the “unhealthy for sensitive groups” category, which includes people with asthma, respiratory conditions, young children, and older adults.
If you’re part of a sensitive group, it’s a good idea to limit your time outdoors, keep your windows closed, and consider wearing a well-fitting N95 mask when you have to go outside. These masks can help reduce exposure to the fine particulate matter found in wildfire smoke.
Elsewhere across Southern Ontario, AQI readings are in the 50 to 100 range, which is considered moderate. That’s not a big concern for healthy individuals, but anyone who is sensitive to air pollution may want to avoid heavy outdoor activities like running or biking.
You might also notice a faint smoky smell in the air, but it's not expected to be too strong. Still, it’s a reminder that there’s pollution present, even if the skies don’t look especially hazy.
UPPER LEVEL SMOKE CONCENTRATION - MAP FROM WEATHERBELL
The smoke is expected to stick around overnight and into Monday morning, especially in the lower levels of the atmosphere. By Monday afternoon, we should begin to see some clearing closer to the surface, with air quality likely improving through the day.
Unfortunately, that improvement probably won’t last long. The latest forecast models show another plume of upper-level smoke moving into the region by late Monday. While these models currently suggest limited smoke near the surface, we’ve seen before that they often underestimate how much smoke actually mixes down. So we can’t rule out more air quality issues as the week goes on.
UPPER LEVEL SMOKE CONCENTRATION - MAP FROM WEATHERBELL
Looking ahead, additional wildfire smoke is a strong possibility, especially as fires continue to grow rapidly across Northwestern Ontario. One major concern right now is the fire near Sandy Lake First Nation, which has prompted a full evacuation of the community. That fire is expected to grow further and could become a major source of smoke for Southern Ontario in the days ahead.
Because of its closer proximity compared to fires in Western Canada, smoke from this fire has a better chance of settling closer to the ground by the time it reaches our region. That means more noticeable impacts, even for those outside of sensitive groups.
SOURCE: CWFIS
Some good news: recent rainfall has helped reduce the fire danger in parts of Ontario, Manitoba, and Northern Saskatchewan—regions that have been hit hard by wildfires over the past couple of weeks. This rain may help slow fire growth and support containment efforts, especially in areas where communities are at risk.
However, the same can’t be said for British Columbia, Alberta, and Southern Saskatchewan. These areas are still facing high to extreme fire danger levels, with dry conditions and tough firefighting environments.
Quebec is also showing some concerning signs, with several pockets of high to extreme fire risk. If wildfires do ignite there, it could add yet another smoke source for Southern Ontario in the coming days.