Which months are wettest and driest in Victoria?

The Gonzales figures describe Fairfield, Oak Bay and the south-facing city core, which sit deepest in the Olympic Mountains rain shadow. The gradient across the region is steep: the airport station in North Saanich records roughly 45% more than the city, the University of Victoria station in Gordon Head about 661 mm, and Sooke and the western hills more again. A December that keeps a James Bay roofer working between showers can shut down a Sooke job for a week.

Wind matters as much as rain for roof scheduling. The fall and winter southeasterlies and the occasional northeasterly that hits Cordova Bay and the Sidney waterfront are what lift shingles and stop crews, and they arrive with the wet-season fronts from October onward. Summer is not only dry but calm, which is why elective replacements on exposed sites in Colwood and Esquimalt are booked for July and August months in advance.

Two things surprise people. First, Victoria is the driest location on the BC coast; 608 mm at Gonzales is a fraction of what the outer coast receives, and the widely copied figure of about 1,100 mm for the city conflicts with the official normals and should not be used. Second, the rain is concentrated: most of the year's total falls between October and April, and July and August are among the driest summer months anywhere in Canada outside the far north.

For roofs the practical consequence is that the damage here comes from six or seven months of damp shade and moss, not from volume. A roof that drains and dries between fronts handles a Victoria winter well; one that sits under trees and never dries does not.

Each kind of job has a natural season.

• Full replacements in asphalt: May to September ideal; shoulder months fine; winter possible section by section
• Cedar and torch-on: dry deck needed, so summer and the driest shoulder weeks
• Moss removal and treatment: after the roof dries in late spring, or early fall before growth resumes
• Gutter and valley clearing: late October before the wet season, and again in spring
• Inspections: any time; a wet-weather visit shows leaks, a dry one shows condition
• Storm repairs: whenever they happen; expect queues after a regional wind event

Everything elective wants the same 20 weeks. Two Victoria contractors publish the view that summer, or August specifically, is the best time to replace a roof, and one adds that it is the busiest season and homeowners should book early. Add the spring moss reveal, when soft shingles are found under the winter's growth, and the pre-listing rush before fall real-estate season, and July starts are committed by April. If your roof is sound and the work is elective, a late-April or early-October start often gets a good crew sooner with weather that is nearly as reliable.