For the most recent series of floods, see 2025 Pacific Northwest floods.
The 2021 Pacific Northwest floods were a series of floods that affected British Columbia, Canada, and parts of neighboring Washington state in the United States. The flooding and numerous mass wasting events were caused by a Pineapple Express, a type of atmospheric river, which brought heavy rain to parts of southern British Columbia and northwestern United States. The natural disaster prompted a state of emergency for the province of British Columbia.