An air-quality warning remains in effect for parts of Metro Vancouver and the Fraser Valley due to smog and wildfire smoke from a blaze that has prompted evacuation alerts for the Yale and Spuzzum areas.
It comes as Environment Canada warns that temperatures in the Fraser Canyon and South Thompson regions are expected to reach 37 to 39 C this week, posing a "moderate" risk to public health.
The forecast follows a hot weekend during which nearly two dozen areas set or tied daily maximum temperature records on Sunday.
They include Whistler, where the mercury hit 35.1 C, surpassing the record of 34.3 C set in 1988, and Kelowna, where the temperature of 36.2 C overtook the previous record of 35 C set in 1999.
The smog warning spans eastern areas of Metro Vancouver as well as the central Fraser Valley, while the smoke warning covers eastern parts of the valley.
The regional district says the smog, also known as ground-level ozone, is the result of local emissions combining with hot and sunny weather that saw the temperature in Lytton hit a national high of 40 C on Sunday.
The district says smoke from the Sailor Bar wildfire burning in the Fraser Canyon has also resulted in elevated levels of fine particulate matter in the air.
The fire has prompted the Fraser Valley Regional District to issue an evacuation alert stretching from Yale and north to the Spuzzum area, covering properties on both the east and west sides of the Fraser River.
The Spuzzum First Nation has also issued an alert for properties on several reserves, with residents told to get ready to leave on short notice.
The 120-hectare blaze about seven kilometres north of Yale is one of four wildfires classified as burning out of control across B.C., among just under 70 active blazes.
The air-quality warnings were expected to last until at least Tuesday.
The heat in the Fraser Canyon and South Thompson regions is set to persist until the latter half of the week, with cooler temperatures expected by next weekend.
A heat warning is also in place for inland areas of the north and central coasts, where weather office says the mercury is expected to hit 29 C in the Terrace and Kitimat areas over the next several days.
It says a cooling trend is expected later this week in those regions.
Environment Canada has encouraged people in areas covered by air quality advisories to consider postponing or limiting outdoor activities.
The weather office notes air pollution is more likely to affect infants and children, people aged 65 or older, those who are pregnant or have existing illnesses or chronic health conditions, and outdoor workers.
It says people should seek medical attention in the event of symptoms such as chest discomfort, shortness of breath, severe coughing and dizziness.
This report by The Canadian Press was first published Aug. 25, 2025.
The Canadian Press
