Cities in the Pacific Northwest of North America reported power outages Tuesday, both from failures of utility companies and rolling blackouts due to heavy power demand.
Seattle and Portland temperatures were expected to fall Tuesday, below Monday's record highs, but inland, the city of Spokane, Washington, continued to record high temperatures and experience rolling blackouts in the city.
Lytton, British Columbia, set Canada's all-time high temperature Sunday with 46.6 degrees Celsius, only to see it broken less than 24 hours later, hitting 47.9 C Monday.
Officials said Tuesday that several deaths in Portland and Seattle were tied to the extreme heat. In Vancouver, British Columbia, first responders have said that as many as two dozen deaths may be attributed to the high temperatures.
On Tuesday, the U.N. World Meteorological Organization called the heat wave hitting the Pacific Northwest corner of the United States "exceptional and dangerous" and says it could last at least another five days.
Speaking to reporters from Geneva, a WMO spokeswoman said while records have fallen in the U.S. states of Oregon and Washington, western Canada has seen extreme heat as well.
The official said the temperatures for this time of year and location are shocking. "It's in the province of British Columbia, it's to the Rocky Mountains, the Glacier National Park, and yet we're seeing temperatures which are more typical of the Middle East or North Africa."
In an area used to temperatures 20 to 30 degrees cooler, the WMO said, the extreme heat poses major health threats to residents as well as agriculture and the environment.
The WMO said the extreme heat is caused by "an atmospheric blocking pattern," which has led to a "heat dome" — a large area of high pressure trapped by low pressure on either side. The organization said the temperatures would likely peak early this week on the coast and by the middle of the week in the interior of British Columbia. Afterward, the baking heat is expected to move east toward Alberta.
On its Twitter account late Monday, the U.S. National Weather Service in Portland, Oregon, reported cooler air was already in the region along the coastline.
In a tweet Sunday, the Oregon Climate Service said that the climate system is no longer in a balanced state, and that such heat events "are becoming more frequent and intense, a trend projected to continue."
This report includes information from The Associated Press.