Wildfire frequency, intensity, and severity are increasing across the Western U.S. Significant tree mortality can occur years after fire events, but this has received little attention compared to the immediate tree loss during a fire. We overlapped forest cover loss data with burn severity maps in the U.S. Pacific Northwest and quantified the total and delayed forest canopy loss after fires. We found that wildfires resulted in total canopy losses of 89%, 67%, and 31% within three years in areas burned at high, moderate, and low severity, respectively. The delayed canopy loss accounted for approximately 1/3, 1/2, and 2/3 of the total canopy loss for high, moderate, and low severity burns. Delayed canopy loss was greater in moist and cool areas than in dry and warm areas, possibly because tree species in the wetter areas are less adapted to tolerate fires with traits such as bark thickness and crown height. Across all forests, delayed canopy loss was greater in dry and warm years. These results suggest greater canopy losses will occur as wildfires expand into areas that historically experienced infrequent fires.