Canada expands climate attribution to extreme rain, finding warming made recent downpours up to 10 times more likely.

Canada’s Environment and Climate Change department is expanding its rapid climate attribution system, originally for extreme heat, to assess how climate change affects extreme rainfall. Since June 2025, it has analyzed 42 major rain events, finding most were up to twice as likely due to global warming, with three—like a July downpour on Baffin Island—up to 10 times more probable. The program uses climate modeling to compare pre-industrial and current conditions, aiming to deliver timely insights during public attention peaks. The effort gains urgency as southern British Columbia faces flooding from an atmospheric river, echoing prior findings that climate change made the 2021 B.C. event 60% more likely. The initiative supports emergency planning and long-term adaptation.