Oregon declared a state of emergency as the Pacific north-west prepared for triple-digit temperatures mere weeks after a deadly heatwave clobbered the region. People streamed into cooling centers and misting stations on Wednesday amid sweltering heat.
Governor Kate Brown said: “Oregon is facing yet another extreme heatwave, and it is critical that every level of government has the resources they need to help keep Oregonians safe and healthy.”
The declaration went into effect on Tuesday, amid concerns over the safety of residents, some of whom do not have air conditioning, and the impact the soaring temperatures could have on critical infrastructure. The order is expected to remain in place until 20 August.
Temperatures soared to 97F (36.1C) by the evening in Portland on Wednesday.
In a “worst-case scenario”, the temperature could reach 111F (44C) in some parts of western Oregon by Friday before a weekend cooldown, the National Weather Service warned. But temperatures are more likely to rise to 100F or above for three consecutive days, peaking around 105F on Thursday.
Sizzling weather also was expected in other parts of the country. The NWS said heat advisories and warnings would be in effect from the midwest to the north-east and mid-Atlantic through at least Friday.
Brown, the governor, recommended Oregonians take proactive steps to keep cool, including staying well hydrated; visiting one of the dozens of cooling centers at libraries, community centers and other spaces across the state; and watching out for neighbors, friends and family.
The heatwave arrives less than two months after record-high temperatures, which in some areas exceeded 115F (46C), resulted in hundreds of deaths across the Pacific north-west and western Canada.
Meteorologists reported that the extreme temperatures came from two pressure systems, while a study from World Weather Attribution determined that the heatwave would have been “virtually impossible without human-caused climate change”.
This week’s heatwave is also the result of a high-pressure system forming over the north-east Pacific. But the temperatures are expected to be more intense as a direct result of the climate crisis, said Larry O’Neill, Oregon’s state climatologist.
And the fact that temperatures in some areas are expected to climb into the triple digits for the second time this summer is also significant. “This would be kind of a heatwave that maybe we experience every two to three years in the past, but this will be the second strong one this summer,” said O’Neill.
![A volunteer at a cooling center in Portland.](https://i.guim.co.uk/img/media/73c44679dcc510a813060e3c62b03d2fa5a2e269/110_0_3300_1980/master/3300.jpg?width=445&dpr=1&s=none)
O’Neill said: “Each consecutive day that we have over 100-degree weather is when the impacts really compound and we start to see more and more adverse impacts on public health and also on agricultural livestock production, things like that.”
Jon Bonk, a meteorologist at the NWS in Portland, said that, similar to the heatwave in late June, temperatures in many areas of the region were not expected to cool significantly at night. The Willamette Valley and the Portland metropolitan area, for example, typically see their temperatures cool to the 50s or lower 60s at this time of year, but they may not get below 70F later this week.
“The folks that are used to receiving relief at night just by opening their windows, say, if they don’t have air conditioning, they’re not getting quite that same relief that they’d ordinarily expect,” he said.
Portland’s mayor, Ted Wheeler, also declared a state of emergency.
Washington state is expected to see extremely high temperatures too, with an excessive heat warning across much of the eastern half of the state. The city of Yakima could see triple digits four days straight beginning on Wednesday, according to the NWS. Seattle is expected to be slightly cooler, with temperatures in the low or mid-90s.
Meanwhile, in California, the state’s largest single wildfire in recorded history continued to grow after destroying more than 1,000 buildings, while authorities in Montana ordered evacuations as a wind-driven blaze roared toward several remote communities.
The east end of northern California’s Dixie fire flared up as afternoon winds increased, fire officials said.
Burning through bone-dry trees, brush and grass, the fire has destroyed at least 1,045 buildings, including 550 homes, in the northern Sierra Nevada. Newly released satellite imagery showed the scale of the destruction in the small community of Greenville that was incinerated last week during an explosive run of flames.
The fire is 30% contained, according to Cal Fire. Fire crews are bracing for rising temperatures and declining humidity in coming days.
The cause of the Dixie fire was under investigation. Pacific Gas & Electric has said it may have been sparked when a tree fell on one of its power lines.
California authorities arrested a man last weekend who is suspected in an arson fire in remote forested areas near the Dixie fire. Gary Maynard, a 47-year-old former college professor, has been charged with intentionally setting the Ranch fire in Lassen county, according to court documents. Maynard denies setting the fire, the papers say.
And in south-eastern Montana, communities in and around the Northern Cheyenne Indian Reservation were ordered to evacuate as the uncontrolled Richard Spring fire grew amid erratic winds.
The Associated Press contributed to this report