90s in Seattle, 110s in Phoenix: A New Heat Wave Is Building Across the West

The first official days of the astronomical summer will certainly feel like it across much of the Pacific Northwest. A new wave of record-challenging heat will envelop this corner of the country to start the new work week. Read on for the details of this building heat wave.

Seattle and Portland Could Break Records Set Over 30 Years Ago

Temperatures will soar into the early 90s this week up and down the Interstate 5 corridor in the northwestern U.S. The heat wave will hit less than 10 days after the mercury climbed to new records in cities such as Seattle and Portland. During the June 13 - 15 heat wave, Seattle set a new record high of 91 degrees, and Portland saw a record-breaking reading of 97 degrees.

A dome of high pressure building over the Northwest will be blamed on the incoming heat. Past daily high records may be in danger of falling on Monday and Tuesday. The heat will come after a pleasant weekend featuring perfect temperatures and dry conditions. The latest forecast models signal that temperatures will climb 15 to 20 degrees over the readings notched on Father's Day weekend.

Not only will temperatures likely eclipse what was seen earlier in the month, but forecasters also believe that readings may challenge the daily high records that were set during an early-season heat wave in June of 1992. During this extreme weather event, Portland saw temperatures reach the century mark.

The forecast for Portland is calling for highs in the 90s for the next few days. Tuesday is expected to be the peak of the heat in the Rose City.

Seattle's forecast is also predicting the possibility that temperatures may inch past the readings set during the 1992 heat wave. That event brought highs of 92 degrees to the Emerald City on June 22 - 24.

While it will cool slightly on Wednesday, it will remain unseasonably warm for the next World Cup match at Seattle Stadium. Fans and players at the match between Bosnia-Herzegovina and Qatar will see highs hovering in the mid 80s. Real feel readings will land even higher when combined with the intense sunshine during the peak afternoon heating hours.

A kickoff time of noon means that those in attendance will be dealing with the hottest part of the day. Staying well-hydrated is the best strategy to protect yourself from heat-related illnesses if you are headed out to the game. Although a good chunk of Seattle Stadium is under cover, the field and lower-level seats are exposed to the elements.

Relief Arrives by Thursday — But the Heat Stays Locked Into the Southwest

The zone of high pressure will begin to lose its grip on Wednesday. Temperatures will fall noticeably starting on Thursday. In addition, the southward dip in the jet stream ushering in the cooler temperatures will also come with the threat of rain in the Northwest for the last weekend of June.

For instance, Seattle will see temperatures tumble into the mid 60s for highs by Friday. The city will also see the chance of rain increase on Friday and Saturday. Winds out of the south-southwest at 10 to 15 mph will make it feel even cooler. Overnight lows will bounce around in the mid 50s during this stretch.

Rain will also return to Portland on Friday. Like Seattle, the mercury will struggle to climb out of the mid 60s.

It will remain hot farther to the south in the western U.S. The heat will persist in an area from Central California and into the Four Corners. Places such as Phoenix will reach the 110s by the middle of the week. This is sizzling even by Phoenix standards, coming in at about 10 degrees over the historical average for the end of June.

It will also be unseasonably hot in metro areas such as Salt Lake City. The largest metro area in Utah is bracing for highs to skyrocket into the upper 90s on Tuesday and Wednesday. Ample sunshine will add to the heat. Temperatures will return to more seasonable levels on Saturday with a forecast high of 80 degrees under partly cloudy skies. Readings will max out in the mid 70s on Sunday, delivering a beautiful day for outdoor activities.

Those in California's Central Valley should also prepare for very warm conditions. Fresno is forecast to be under the gun for several days in the 100s. This magnitude of heat will get its start on Monday, expected to persist through at least Thursday.

Climatologists have been warning for months that this is shaping up to be a scorcher of a summer for much of the nation. This means that this is likely just the first of many heat waves in store for the western U.S. Stay tuned as we continue to provide updates as the summer progresses.

Weather changes fast, so help your community stay prepared. Share this story with friends, family, or your group chat, and keep your forecast in the now with Weather Forecast Now.