The number of low-visibility hours in Williams Lake, B.C. each wildfire season due to smoky weather. 'Low visibility' is defined as when visibility is between 0 and 6 miles by Environment Canada. Wildfire season in this sample stretches from May to October. 2023 data as of Sept. 21. The chart periodically sees jumps of up to 300 low-visibility hours, but jumped to an astronomical 873 hours in 2023.