An unusually early heatwave is set to sweep through the Pacific north-west of the US this weekend as the region braces for potentially record-breaking temperatures.
On Saturday, the National Weather Service (NWS) warned that “much above average to record heat building [will occur] across the Pacific north-west” as temperatures reach the high 80s and 90s degrees Fahrenheit, with the warmth expected to spread into the Rockies and Great Plains by early next week.
The NWS has issued a heat advisory for parts of Oregon and Washington that is expected to last until Sunday night.
“Hot temperatures may cause heat illnesses to occur,” the NWS said, adding that residents should drink plenty of fluids, stay in air-conditioned rooms, keep out of the sun, and check up on relatives and neighbors. It also warned that young children and pets should never be left unattended in vehicles under any circumstances.
Washington’s King county, where Seattle is located, has directed transportation operators including bus drivers to let people ride for free if they are looking to cool off or are headed to a cooling center, the Associated Press reports.
The heatwave is expected to worsen wildfires that are currently burning in western Canada. On Thursday, 75 active wildfires burned in Alberta, with 23 listed as out of control. The fires have already displaced thousands of residents and many more are being placed under evacuation orders.
According to NWS meteorologist Daniel Hartsock, the rise in the region’s temperature comes as a result of an intense high-pressure system similar to the “heat dome” that trapped hot air across the region in a record-breaking heatwave two years ago.
“We’re looking at temperatures 20 to 25 degrees above normal, so that’s definitely not very common,” Hartsock told Oregon Public Broadcasting, adding that the average high is around 70F (21C) in mid-May.
Last July, at least 14 people in Oregon were suspected to have died as a result of a blistering heatwave that spread across the Pacific north-west as then governor Kate Brown declared a state of emergency in 25 counties across the state.
In 2021, more than 100 people died from Oregon’s heatwave, mostly due to a lack of air-conditioning, heat stroke and heat-caused heart attacks. The heatwave, which saw temperatures as high as 118F (40C) across the Pacific north-west, was described by experts as a 1-in-1,000-year event.
• This article was amended on 14 May 2023 to give the correct highest temperature recorded in the 2021 Oregon heatwave.