An Air Quality Advisory for Metro Vancouver and the Fraser Valley has been issued because of "elevated concentrations of fine particulate matter due to smoke from wildfires burning in British Columbia and the western United States," said a Metro Vancouver news release.
"Levels of fine particulate matter are lower than those experienced during the wildfire smoke events in August, and improvements in air quality are expected to begin overnight and into tomorrow as a significant change in the weather is forecast to bring clean marine air into the region."
"A noticeable haze may continue to be present while elevated levels of fine particulate matter persist," the release says. "Smoke concentrations can vary widely across the region as winds and temperatures change, and as wildfire behaviour changes."
Metro Vancouver is warning that people with chronic underlying medical conditions should postpone strenuous exercise until the advisory is lifted.
"Exposure is particularly a concern for infants, the elderly and those who have diabetes, and lung or heart disease."