Stifling heat to jeopardize August records in the Pacific Northwest

AccuWeather forecasters said Saturday the hottest weather yet this season is about to grip portions of the Pacific Northwest.

The long-duration nature of the upcoming heat wave could put a significant strain on a part of the nation where air conditioning is not prevalent, they warned.

Excessive heat watches and warnings spanned across the Interstate 5 and I-90 corridors on Saturday as locations from Medford and Portland in Oregon to Seattle and Spokane in Washington geared up for their hottest days yet this summer.

The core of the high pressure system that has led to historic heat this summer in places such as Phoenix will expand northward and cause an abrupt shift to intense heat across Oregon and Washington from Sunday into the middle of the week, according to AccuWeather Meteorologist La Troy Thornton.

The upcoming heat burst bears some similarities to August 1981, when temperatures soared to their highest levels ever recorded during the month of August from Medford to Eugene, Salem and Portland in Oregon.

"Portland in particular can approach its monthly record high for August as the heat wave unfolds, with a high in the middle to upper 100s expected on Monday, not far from the monthly record of 107 that was set on August 8 and tied on August 10 during another intensely hot stretch in the year 1981," Thornton said.

The August record-high temperature in Eugene and Salem is 108 also from that year, and both cities could tie or surpass this mark on Monday, according to AccuWeather's forecast.

In Medford, high temperatures are expected to fall short of monthly record territory (114 from 1981), but will still be 10-15 degrees above the historical average, which is the lower 90s, from Sunday to at least Thursday.

Even if all-time record highs are not set amid the heat wave, daily record highs are likely to be smashed for consecutive days.

Temperatures are expected to soar to impressive heights elsewhere across the Pacific Northwest, including much of Washington state, as well as southward into part of Northern California.

Seattle's hottest day yet this summer occurred on July 15 when the thermometer reached 91. AccuWeather meteorologists say the mercury may hit or exceed that mark early next week but should fall short of daily record territory.

Cities farther from the coast such as Spokane and Bend, Ore., should be near the century mark for multiple days in the new week, according to Thornton.

Farther south, Sacramento, Calif., is likely to experience near-record heat in the 100s from Monday to Wednesday.

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. This can make heat waves, particularly ones that are prolonged in nature, particularly dangerous.

Forecasters urge people across the region to take extra precautions, including drinking plenty of water and limiting outdoor activity during the hottest times of the day. Wellness checks on those most vulnerable to the heat, such as children and the elderly, are encouraged."

The extended hot spell will undoubtedly dry out fuels across the Northwest, raising the wildfire danger," AccuWeather Meteorologist Brandon Buckingham said.

Despite a below-average wildfire season so far across the United States in terms of acreage burned, AccuWeather long-range forecasters are predicting a high risk of wildfires across large areas of Washington, Oregon and Idaho into autumn.