Seattle and Portland endure another day of relentless heat gripping the Northwest
AP
By Madeline Holcombe, CNN
The mercury kept climbing Monday in heat-baked Portland, Oregon, and Seattle, again setting record highs.
Canada and US cities in the Northwest are all reporting their hottest temperatures on record in a wave that has more heat in store. More than 20 million people are under a heat warning or advisory, from the Canadian border to the Mexican border.
Seattle had topped its all-time record high Sunday when thermometers climbed to 104 degrees — so hot that even the normally freezing temperatures above 10,000 feet on Mt. Rainier reached 73 degrees.