Metro Vancouver issued the advisory on Sunday, warning residents as far east as the Fraser Valley that high amounts of ground-level pollutants could be expected.
But the agency says temperatures have cooled, the concentration of pollutants is now lower, and as a result air quality has improved.
It says residents may still notice haze in some areas of the region.
Metro Vancouver says haze can occur even when the concentration of pollutants isn't high enough to issue an advisory.
Environment Canada is forecasting reduced temperatures and sun for the region over the coming days but cloud and even rain heading into the weekend.