
Persistent wildfire smoke continues air quality concerns across Ontario
Poor air quality persists across much of Ontario due to wildfire smoke, with limited improvement expected as shifting winds and ongoing fires keep AQHI levels high into the weekend
The air quality health index (AQHI) remained high to very high across much of Ontario as of Friday, with health officials advising residents to minimize time outdoors.
Wildfire activity in northwestern Ontario has led to evacuation orders and has sent thick smoke sweeping across the region and downwind into parts of the province.
RELATED: Ontario's AQHI is soaring. Here's what the numbers mean
Conditions seek to improve Saturday
Southwestern Ontario and the GTA can expect a reprieve as a brief window of ‘clean’ air will arrive by the afternoon. The brief window will help fuel storms along the cold front, bringing in another wave of smoke from the north.
While northwestern Ontario can continue to expect the worst of the smoke due to the direction of the winds. While those same winds will bring less smoke in northeastern Ontario.

Outside of Thunder Bay, no cities in the province should expect to see poor air quality for the full duration of Saturday, which has already seen the worst air quality in the province in recent times.
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Most of Ontario’s major cities have seen hazardous peak air quality in the last 36 hours, with Barrie in very unhealthy and Ottawa just barely having reached unhealthy levels.

Will the rain actually help?
Rain and thunderstorms over the last 12–18 hours have offered modest relief to areas of northwestern Ontario.
RELATED: From flames to forecasts: How wildfire smoke affects your weather
However, lightning poses the risk of further fire starts, while prevailing poor weather conditions continue to sustain wildfire activity and dense smoke production.

WATCH: Rain relief begins in Thunder Bay
For southern Ontario, a trough moving through into Saturday brings the potential for showers and thunderstorms. However, the persistence of smoke could limit precipitation in some areas.
FORECAST: Severe storm, tornado risk in Ontario Saturday: Will smoke play a role?
Uncertainty remains regarding improvements in southwestern Ontario, as wildfire growth and shifting winds may prolong poor air quality conditions into the weekend. Several days of significant rainfall and higher humidity are needed to make a substantial impact.

Health and visibility impacts:
Smoke at low atmospheric levels raises health risks
Increased discomfort for individuals with respiratory conditions
Hazy skies and the smell of campfire
Red sunrises and sunsets
DON'T MISS: The Weather Network's hub for all wildfire information in Canada
Limiting outdoor activity is advised in affected areas.
