The unprecedented Pacific Northwest heatwave of June 2021

In late June 2021 a heatwave of unprecedented magnitude impacted the Pacific Northwest region of Canada and the United States. Many locations broke all-time maximum temperature records by more than 5 °C, and the Canadian national temperature record was broken by 4.6 °C, with a new record temperature of 49.6 °C. Here, we provide a comprehensive summary of this event and its impacts. Upstream diabatic heating played a key role in the magnitude of this anomaly. Weather forecasts provided advanced notice of the event, while sub-seasonal forecasts showed an increased likelihood of a heat extreme with lead times of 10-20 days. The impacts of this event were catastrophic, including hundreds of attributable deaths…

• BH
  BC Hydro
• M
  Mitacs
• AI
  Alberta Innovates

  Award: 2019F163R
• NS
  Natural Sciences and Engineering Research Council of Canada

  Awards: RGPIN-2020-05783, RGPIN-2016-05441
• NR
  Natural Resources Canada