PORTLAND, Ore. – After a record Labor Day weekend heat wave, Portland's high temperature was expected to hit 90 degrees again on Tuesday.

"High temperatures reach the mid to upper 90s through Tuesday," KGW meteorologist Chris McGinness said. "It's possible some backyard thermometers show 100 before this latest heat wave breaks."

Wildfire smoke kept temperatures a bit lower Tuesday. Thunderstorms could arrive in the region later Wednesday, he said.

Forecast | 7-day at a glance

The National Weather Service issued an Excessive Heat Watch for a large area of northwest Oregon and southwest Washington from Friday afternoon through Tuesday night.

Current air conditions

Relief from the heat should arrive Wednesday.

"Wednesday will be a little cooler, but significant relief likely holds off until Thursday as highs drop into the 80s," McGinness said. "We've got a chance of showers and thunderstorms as early as Wednesday evening, more likely Thursday and Friday."

Cooling centers open

Multnomah County

Cooling centers will open Friday, Sept. 1 through Thursday, Sept. 7 at the locations and times listed below:

  • Multnomah County Walnut Park Building, 5325 NE Martin Luther King Jr. Blvd., Portland (Weekdays, 5 p.m. to 8 p.m.; Weekends and Labor Day, 2 p.m. to 8 p.m.)
  • Multnomah County East Building, 600 NE 8th St., Gresham (Weekdays, 5 p.m. to 8 p.m.; Weekends and Labor Day, 2 p.m. to 8 p.m.)
  • Hollywood Senior Center, 1820 NE 40th Ave., Portland (Weekdays, 5 p.m. to 8 p.m.; Saturday and Labor Day, 2 p.m. to 8 p.m.; Sunday, 2 p.m. to 5 p.m.)