Metro Vancouver has ended the fine particulate matter air quality advisory that has been in effect since Sept. 8, saying clean marine air is now flowing through the region.
Environment Canada says air quality in southern and central British Columbia is expected to improve through the weekend as a new weather system moves in, but conditions across the mountains were expected to worsen before getting better.
Smoke from wildfires burning in California, Oregon and Washington state has blanketed B.C., prompting respiratory health warnings on Saturday that extended into southern Alberta and as far east as Saskatchewan.
Environment Canada said smoke was beginning to clear across the western half of Vancouver Island, and there should be widespread improvements farther east by Sunday.
In the central portions of the province, the agency said smoke will be visible at higher elevations with potential for light to moderate effects.
A fine particulate advisory remains in effect for Metro Vancouver and the Fraser Valley because of persisting ground level smoke with airborne solids and liquid droplets.
Farther east, the weather agency was forecasting more smoke in southern Alberta on Saturday, and issued special air quality statements for Jasper and Banff national parks, as well as Calgary and into south-central Saskatchewan.
It said smoky conditions across those areas were expected to worsen throughout the day, causing the air quality to deteriorate in many locations. As a weather system moved through the area Saturday night, conditions were expected to improve by Sunday.
Environment Canada said people with chronic underlying medical conditions or acute infections such as COVID-19 should postpone or reduce outdoor physical activity until the advisories are lifted.