After being hit by several consecutive days of 90 degrees or more that had climbed into the triple digits in some cities, the Pacific Northwest is expected to gain some relief this week before temperatures rise again this weekend, forecasters said.
In Portland, Ore., a heat wave has lasted a week, with a record high for the day set on July 26 at 102 degrees, said Lisa Kriederman, a meteorologist with the National Weather Service in Portland.
Sunday was the seventh day in a row in Portland that temperatures reached 95 degrees or higher, breaking the previous record of six days in a row. Temperatures have been 90 or higher for eight days in a row, still short of the 10-day record set in 2009.
Temperatures in Portland have also not yet reached last summer’s record high of 116 degrees, but this recent heat wave has lasted longer. Cool coastal air keeps humidity levels higher, keeping temperatures from rising as much. That compares with last year when air was coming to Portland from the drier part of Central Oregon, Ms. Kriederman.
“This one doesn’t get as warm, but the above-average temperatures last longer,” he said.
The area is expected to cool through Thursday, then warm up again Friday and into the weekend, Ms. Kriederman. Highs are expected to be 87 degrees on Tuesday, 86 on Wednesday, 78 on Thursday and 83 on Friday. according to the National Weather Service.
Read more about extreme weather
Last month was Portland’s fourth warmest July on record at 73.7 degrees, as measured by the average temperature. The average maximum was 85.7 and the average minimum temperature was 61.8, which was the highest on recordsaid Ms. Kriederman.
The Multnomah County Medical Examiner said Sunday it was investigating two additional deaths suspected to be associated with the heat wave, bringing the total number of heat-related deaths to five. The Clackamas County Medical Examiner’s Office said Saturday that it was investigating the death of an elderly man that may be heat-related.
About 200 miles east of Portland in Pendleton, Ore., the temperature reached 111 degrees Friday, said Larry Nierenberg, a meteorologist with the National Weather Service in Pendleton. Through Sunday, Pendleton recorded seven days of temperatures above 100 degrees, he said.
Smoke from the McKinney wildfire in Northern California caused temperatures in Pendleton to drop from 110 degrees on Saturday to 101 on Sunday. Smoke from wildfires acts like clouds, blocking the sun from coming through for a few hours, Nierenberg said.
The cities of Kennewick, Pasco, Richland and West Richland in southeast Washington had similar patterns, with a high of 112 on Friday. Temperatures have reached 100 or higher on eight consecutive days. That area remained under an excessive heat advisory as of Monday afternoon.
For the past week, Pendleton and Southeast Washington as a whole were 10 to 20 degrees above normal average, which is in the low 90s for Pendleton and slightly higher in the cities, he said Nierenberg.
In eastern Washington and the Idaho Panhandle, average July temperatures were not record highs, said Daniel Butler, a National Weather Service meteorologist in Spokane, Wash.
But there were four straight days when the high temperature reached or exceeded 100 degrees in Spokane, he said. The record for consecutive days of temperatures of 100 degrees or higher, six, was set in 1928.
While the recent heat wave hasn’t brought the hottest days on record, the heat has lasted longer, Butler said.
“It’s been pretty impressive — the longevity of this event,” he said.
