The extreme, yet early season, heatwave that has gripped much of Canada over the past two weeks is showing no signs of abating, and is spreading into Northwestern USA. This heatwave is the result of an abnormally strong high pressure system that is effectively blocking normal atmospheric circulation patterns. Anomalously warm Arctic temperatures are one of the driving factors creating this system. Temperatures in British Columbia, Alberta and the Yukon could rise +18°C above the average highs for this time of year–temperatures usually seen at the peak of the summer in July and August. Heat warnings are also issued for western Washington and Oregon, which are predicted to face similar temperatures.

29,000 people have already been forced to evacuate from wildfires in Alberta, and this furthering heat will bring more challenging fire-fighting conditions. The perpetuating heat, in addition to continued drought, is priming fodder for further fires. In addition to fire, this heat accompanies health risks, especially for young children and older adults, outdoor workers and marginalised communities. Health impacts are magnified by poor air quality as a result of the wildfires–particulate matter of which has now reached across the continent.

Climate Central’s analysis shows this North American heatwave is 5x more likely as a direct result of human emissions.

Many of the extreme heat events we are seeing globally would be virtually impossible without human-driven climate change. Former Arctic Basecamp research fellow, Maja Vahlberg, co-authored a piece published this week finding that the excessive heat throughout the Iberian Peninsula and northern Africa was also a consequence of anthropogenic climate change.