Environment and Climate Change Canada warns western Canadians about dangerous record-high temperatures

Canadians are already feeling the impacts of climate change through more frequent and extreme weather events, including heat waves, wildfires, floods and droughts.

Environment and Climate Change Canada's Meteorological Service is continuing to warn Canadians about a dangerous and unprecedented heat wave, which is expected to persist in British Columbia, Alberta, Saskatchewan and parts of the Northwest Territories this week. This event is already shattering longstanding temperature records, especially in British Columbia.

This severe weather event is bringing record temperatures well above 35°C (some exceeding 45°C) in several areas of western Canada this week. These extreme daytime highs are expected to persist well above normal right through July 1. Furthermore, the nighttime lows will not drop enough to bring relief to those in the most impacted areas.

Environment and Climate Change Canada is urging western Canadians to heed public health warnings and stay hydrated, avoid spending long periods of time outdoors, seek shelter, and check on neighbours and loved ones who may have pre-existing health conditions that make them more susceptible to heat stroke and heat exhaustion.

On June 28, 2021, Lytton, British Columbia, reached an all-time Canadian heat record of 47.9°C, beating the previous day's record of 46.6°C. These 2021 heatwave temperatures broke the previous record of 45.0°C set in July 1937, in Saskatchewan. Other records broken across British Columbia, Alberta, the Yukon and Northwest Territories include 91 daily maximum temperatures and 181 warm overnight low temperatures. Many of these daily records were exceeded by 5-10°C. Some other notable extremes include the following warmest all-time maximum temperatures observed in BC at the following locations:

Cache Creek, BC: 45.0°C (old record 40.1°C in 2015)

Lillooet, BC: 44.8°C (old record 39.8°C in 2015)

Kamloops, BC: 44.0°C (old record 38.2°C in 2015)

Trail, BC: 42.3°C (old record 40.6°C in 2015

Clearwater, BC: 42.3°C (old record 36.9°C in 2015)

Merritt, BC: 42.2°C (old record 38.0°C in 2015)

Osoyoos, BC: 42.0°C (old record 40.9°C in 2015)

Castlegar, BC: 41.5°C (old record 39.7°C in 2015)

Kelowna, BC: 41.5°C (old record 38.1°C in 2015)

Vernon, BC: 41.5°C (old record 37.3°C in 2015)

The extreme heatwave is caused by a significant atmospheric blocking pattern where a massive dome of hot air, reaching high into the atmosphere, remains stagnant over western North America.