'Life-threatening' heat wave begins in the Northwest
Click here for the latest story on the grueling and record-shattering Pacific Northwest heat wave.
A historic and "life-threatening" heat wave is underway across the Pacific Northwest, the likes of which -- in terms of high temperatures and duration -- has never been experienced before in that part of the country. AccuWeather forecasters are calling for record-shattering heat to linger through early week, not only making life miserable for a part of the country where air conditioning is not prevalent but also posing a significant health risk to millions.
Consecutive days of high temperatures well into the triple digits are forecast throughout parts of Oregon and Washington, which includes the Interstate 5 corridor. Both Portland, Oregon, which could see the mercury crack the 110-degree-Fahrenheit mark, and Seattle, which is expected to top 100, will see temperatures soar 30 to 40 degrees above normal. Points farther inland are likely to have temperatures balloon to above 115.
Average highs in June can be anywhere from the 70s in eastern Washington and Oregon to the 80s in western areas and into Idaho.
The dangerous heat is forecast to peak through Monday as high pressure settles in and enables temperatures to climb to new heights.
Even prior to the peak of the heat, Port Angeles, Washington, which sits on the northern edge of the Olympic Peninsula, rose to an all-time record high of 95 degrees Fahrenheit on Friday. The city would normally experience a high of 64 on the date.
U.S. National Weather Service advisories for the Pacific Northwest, as of Friday morning.
"There are typically a few rounds of heat in the Pacific Northwest each summer, but this particular heat wave looks quite extreme," said AccuWeather Meteorologist Brian Thompson, who regularly analyzes weather patterns in the West.
Excessive heat watches and warnings, as well as red flag warnings for high fire risk, were plastered across the Northwest and across the United States and Canada border, issued by both the United States National Weather Service (NWS) offices and Environment Canada.
Temperatures in Sunnyside, Washington, are expected to soar to an incredible reading of 118. The all-time state record high temperature for Washington is 118, most recently set at Burbank, Washington, near Sunnyside, about 220 miles southeast of Seattle, on Aug. 5, 1961.
The state of Oregon can also reach its own all-time record of 117. The all-time record high was set in Umatilla, Oregon, on July 27, 1939.
One of the largest impacted cities in the Northwest will be Seattle, where temperatures already broke the monthly record high of 96, which has been locked in a three-way tie since 2017, when the city reached 102 degrees on Saturday. This was the second warmest temperature on record since 1945, according to the NWS.
Typically, the Emerald City has highs in the lower 70s at this time of the year.
Temperatures are forecast to spike to 110 in Seattle on Monday, which would not only shatter June's monthly record high, but also break the all-time record at the Seattle-Tacoma Airport of 103 set on July 29, 2009.
AccuWeather RealFeel® Temperatures are anticipated to rise multiple degrees higher than thermometer temperatures and can surpass 110 in some locations as heat peaks in the afternoons.
This extreme heat will be the result of a large northward bulge in the jet stream.
"When the jet stream behaves this way, the air at mid- and upper levels of the atmosphere becomes very warm," explained AccuWeather Senior Meteorologist Alex Sosnowski. This upper-level heat can allow the surface to easily heat up.
"Heat can be especially dangerous in the Pacific Northwest because air conditioning is not as common as the rest of the country," said Thompson.
Seattle Mayor Jenny Durkan issued a reopening of several public spaces with air conditioning, at a limited capacity. This will not only be extremely helpful for those without houses, but for many other residents as well because only about a third of homes in the Seattle metro area have air conditioning, according to the U.S. Census Bureau’s American Housing Survey.
Although air conditioners are growing more popular in Washington and Oregon in recent years, not every resident has the means to keep their home cool, according to the U.S. Department of Labor.
Farther south down Interstate 5, Portland Mayor Ted Wheeler said on Twitter that cooling centers that opened on Friday, June 25, throughout Multnomah County would remain open at least through Monday, June 28. One of the locations that will serve as a cooling center is the Oregon Convention Center in Portland.
“This is life-threatening heat,” Multnomah County Health Officer Dr. Jennifer Vines said in a statement. “People need to find someplace cool to spend time during the coming days. And for people who already have somewhere cool, their job is to reach out to other people. Ask them to join you, or help them get to a place that is reasonably cool.”
AccuWeather forecasters are predicting a high of 114 on Sunday at Portland International Airport, which would demolish the city's all-time record high of 107 set on multiple dates in July and August, reached most recently during the summer of 1981. Forecasters say the mercury will hit 110 in downtown Portland.
On Saturday, Portland broke its all-time record high for any month as the mercury soared to 108. The previous all-time record high was 107 set on multiple dates in July and August, reached most recently during the summer of 1981.
"Temperatures of 110 F or greater are virtually unheard of west of the Cascades, but it’s not out of the question that Portland, Oregon, could see temperatures eclipse that mark for the first time in recorded history on either day," said AccuWeather Senior Meteorologist Randy Adkins. Even if high temperatures stay below this mark, they are expected to remain well above average for at least the next seven to 10 days.
Relief is not coming at night, either, as overnight lows are anticipated to be elevated as well. This can raise energy demands as residents plug in fans to keep cool while they sleep, which can also increase energy bills. Furthermore, fans are known to increase the risk for dehydration.
While fans can be an effective means of reducing body temperature by evaporating perspiration, they can accelerate dehydration in some cases, according to Sosnowski.
“The research we have shows it’s those nighttime lows that are really important to health,” said Brendon Haggerty, interim supervisor for Multnomah County Health Department’s Healthy Homes and Communities. “People rely on those temperatures to recover and to cool down their homes, but nights are not going to provide the relief we might normally get.”
"The situation isn’t any better in Canada," Adkins said.
This heat is unparalleled, rivaled only by the heat wave of July 1936 in Manitoba and Ontario which lasted for nearly two weeks and claimed the lives of nearly 780 Canadians.
The all-time record high for British Columbia is 112 F, which is about 44 degrees Celsius, recorded in 1941. The record for all of Canada is 113 F, or 45 C, set in 1937 in Midale and Yellowgrass, Saskatchewan.
"Those numbers could possibly be reached or eclipsed early this week across southern British Columbia," Adkins said.
There is still snow on parts of the higher Canadian mountains, and snowmelt can cause rivers and streams to run quickly and even flood as water levels rise. Roads and railroad tracks can also buckle due to extreme heat, which can be hazardous for motorists and train operators.
"Typically, extreme heat does not last that long in the Northwest," said Thompson. This bout of heat will linger, and could last three days in some areas.
A key indicator of a warming climate, the number of new record high temperatures is outpacing the number of record lows in Seattle (Climate Central).
Residents are urged to take precautions like drinking plenty of water and remaining inside air-conditioned buildings if possible to avoid heat-related illnesses. People are also being reminded to take care of animals by bringing pets indoors if it's cooler than outdoors. If an animal does spend time outside, make sure they have access to shade and water.
"The anomalous heat will last a week or more in British Columbia as well and make this heat wave particularly dangerous," Adkins added.
Many coastal locations are likely the only parts of the region that will be spared from the scorching heat, forecasters say.
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