Record-setting extreme heat wave killed more than 600 people in B.C.

Environment Canada heat warnings covered most of British Columbia and Alberta one year ago as a so-called heat dome settled in.

The B.C. provincial coroners' service linked more than 600 deaths to the extreme heat, with 93 per cent of them occurring June 25 to July 1. Alberta's medical examiner saw 66 more reported deaths during the heat wave, but couldn't definitely say they were caused by the heat.

June 24: Environment Canada issues warnings about extreme temperatures for almost all of B.C. and into Alberta. The weather office says the risk of wildfires and potential for illness linked to heat or poor air quality will likely rise.

June 25: B.C.'S Ministry of Public Safety releases a statement asking residents to take precautions as Environment Canada predicts a “dangerous, long heat wave” with little relief at night.

June 27: Sixty daily temperature records fall in communities across B.C.; records are broken in Alberta and the northwestern U.S. The mercury in the Interior village of Lytton climbs beyond 46 C, breaking the all-time Canadian high of 45 C set in 1937. Environment Canada describes the heat wave as “prolonged, dangerous, and historic.”

June 28: Lytton sets another Canadian temperature record at 47.9 C, while more than a dozen school districts across B.C. cancel classes for the day due to the heat.

June 29: Environment Canada says 91 maximum daily temperatures and 181 warm overnight low temperatures are broken across B.C., Alberta, Yukon and Northwest Territories. It says many daily records were shattered by five to 10 degrees. The temperature in Lytton sets another Canadian heat record, which still stands today, reaching 49.6 C.

June 30: A wildfire moves through Lytton “with ferocious speed,” giving residents minutes to get out. The extreme heat eases for parts of B.C., Yukon and Northwest Territories, but Environment Canada warns that conditions remain dangerously hot across southern and central B.C. and east to Manitoba.

July 2: Chief coroner Lisa Lapointe says it's believed two people died in the wildfire that swept through Lytton. She also reports that the number of sudden and unexpected deaths during the heat wave was three times what is normal.

June 7, 2022: The B.C. coroner's death review panel report shows more than half of the 619 deaths happened on June 28 and 29, the days with the highest temperatures. The review found there was a “lag” between the heat alerts issued by Environment Canada and the response by public agencies.