top of page


An extreme heat wave affected much of Western North America from late June through mid-July 2021.

Rapid attribution analysis found this was a 1000-year weather event, made 150 times more likely by climate change. The heat wave affected Northern California, Idaho, Western Nevada, Oregon, and Washington in the United States, as well as British Columbia, and, in its latter phase, Alberta, Manitoba, the Northwest Territories, Saskatchewan, and Yukon, all in Canada.

The heat wave appeared due to an exceptionally strong ridge centered over the area, whose strength was linked to the effects of climate change.

It resulted in some of the highest temperatures ever recorded in the region, including the highest temperature ever measured in Canada at 49.6 °C (121.3 °F), as well as the highest temperatures in British Columbia, in the Northwest Territories, and, according to preliminary data, also in Washington.

The record-high temperatures associated with the heat wave stretched from Oregon to northern Manitoba, and daily highs were set as far east as Labrador and as far southwest as Southern California. However, the Pacific Northwest sustained most disruption and damage connected with the extreme weather event.

The heat wave sparked numerous extensive wildfires, some reaching hundreds of square kilometers in area, which led to widespread disruption on the roads. It was during this heatwave that the Trozzo Creek Wildfire started. A wildfire destroyed downtown Lytton, British Columbia, the day after it had set a record high temperature for Canada. The heat also damaged to the road and rail infrastructure, forced closures of businesses, disrupted cultural events and melted snowcaps, in some cases resulting in flooding.

The heat wave also caused extensive damage to crops across the region, which will likely to result in higher food prices globally, though the losses have yet to be calculated.


Featured Posts
Recent Posts
bottom of page