WINTHROP, Wash. — Forty-four fans arrived at the Ace Hardware store in this retreat town of about 400 residents nestled into the eastern folds of the Northern Cascades on Thursday. By Saturday, they had all been snapped up.

A new batch arrived the next day, Ruthie said from behind the register, and already the 20-inch, 10-inch and 5-inch models were gone.

Next door at the Thriftway, a steady stream of shoppers hoisting packs of water and bags of ice emerge into a scorching parking lot. At a Home Depot in nearby Omak, a security guard watched over a new pallet of air conditioning units.

The heat wave baking the Pacific Northwest has set consecutive daily temperature records in Seattle and Portland, sending the mercury to heights more common in Phoenix in August. Seattle hit a high of 106, the highest temperature ever recorded; in Portland, the temperature hit 115.

In Portland, Emily Baier, a software engineer, ha just moved into a new house, the first she has ever lived in with air conditioning. After a brief trip outside, she sent a text message with an expletive.

“I just went outside to put the trash out and during the 20 seconds it took it felt like my skin was on fire,” she wrote. 

Even the normally staid and unflappable National Weather Service expressed an uncharacteristic tone of surprise.

“As there is no previous occurrence of the event we’re experiencing in the local climatological record, it’s somewhat disconcerting to have no analogy to work with,” a National Weather Service meteorologist wrote in a Sunday night update. “Temperature records will fall in impressive fashion. Stay cool, stay hydrated.”

Temperatures on the west side of the Cascades eased Monday night, while triple-digit highs are still on order for much of eastern Washington and Oregon. Winthrop’s Methow Valley is a destination for cross-country skiers; on Tuesday, it will hit 111.

Residents of other parts of the country are used to the occasional 100-degree day, secure in the knowledge they can ride out the heat in homes buzzing with the hum of central air. But in Seattle, air conditioning is not a feature in most new homes — because it was seen as an unnecessary expense.

Native Seattleites grow up with an old joke: You know you’re from Seattle if you know more people who own a boat than have an air conditioning system.

Just 44 percent of housing units in the Seattle metropolitan area are air conditioned, according to the U.S. Census Bureau, the lowest rate of any metro area in the nation. About three-quarters of homes in Portland have such systems.

By contrast, nearly 98 percent of homes in the Washington, D.C., area have AC units. So do more than 99 percent of homes in New Orleans, Houston, Atlanta and Miami.

Jaki McQuiston, who owns a co-working space north of Seattle, is considering adding her home to the minority with an air conditioner. In a changing climate in which heat domes and extreme weather become more common, she said, the price might be worth it.

“This doesn’t happen very often. It’s a big expense to do, but who knows, if this keeps happening, we may reconsider,” she said.

Several area residents compared the heat to an inferno.

“Opening the front door was kind of like opening the door of an oven,” said Hayden Bass, a librarian in Seattle’s Greenwood neighborhood. “The commute, though, was great. There was no traffic. Everybody is staying as close to home as they can.”

Bass’s is one of 27 branches of the Seattle Public Library, and one of just 10 that have air conditioning. By the middle of the afternoon, 119 people were in her building, maintaining their social distance as best as possible.

“There were folks waiting when we opened the doors at 10 a.m.,” Bass said. “It’s fairly crowded, but people are being super respectful.”

Across the region, city and county governments opened cooling systems in libraries, senior centers and an armory. Families flocked to Lake Washington and to splash parks around the area. Fire fighters spent the day delivering ice and water. 

At least four pockets in a three-mile stretch of Interstate 5 north of Seattle buckled under the heat. Puget Sound Energy, Washington’s largest utility, reported 116 active outages, and several thousand customers were without power in Spokane, as well.

Nonprofit groups are opening their doors to those experiencing homelessness. Seattle’s two major transfer stations closed early to protect city workers from the heat. A restaurant in the famed Pike Place Market is offering 10 percent off bowls of chilled gazpacho.

“The heat is pretty bad,” said McQuiston, who took the day off to care for her two daughters. “We were outside with the sprinkler and that helped a bit.”

A new weather system coming off the Pacific Ocean will ease temperatures into the low 90s on Tuesday, and into the mid-80s for the rest of the week in Seattle, the National Weather Service predicted — still unseasonably warm, but cool relief by comparison.

For McQuiston, that means her 5-year-old gets to go to camp.

“My older daughter was supposed to start soccer camp this week,” she said. “I doubt anyone actually showed up.”