Massive Heat Wave Will See 100 Degree Weather Sweep Across the U.S. This Week

A massive heat wave will build in the southern U.S. and expand into the Pacific Northwest this week, with temperatures in the Southwest rising to as much as 120F (49C) on Thursday, Friday and Saturday.

“The Southwest US is going to be seeing very hot temperatures the entire week,” says Andrew Orrison, a forecaster with the US Weather Prediction Center. “This is going to be a pretty significant heat wave that is going to expand in coverage and magnitude.”

High temperatures are also expected across northern Mexico.

Orrison says the heat will move into the Pacific Northwest as it expands over the course of the week. Temperatures in Portland, Oregon, are expected to approach 90F (32C) by the end of the week. In addition to the high temperatures, red flag fire warnings have been posted across parts of Oregon and Washington.

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Excessive heat watches and warnings are in place over parts of California, Nevada and Arizona, where widespread temperatures above 100F are forecast, and heat advisories have been posted in counties across New Mexico, Texas and Florida. San Antonio is forecast to reach 102F Monday and stay there through the week, while Dallas will be that hot starting on Wednesday. Houston will reach 98F, but the humidity will make it feel even hotter, the weather service said.

The weather service warned residents in parts of California, Arizona and along the Colorado River of “dangerously hot afternoons with little overnight relief expected.” The high temperatures are forecast to bear down through next week.

Prolonged exposure to heat has a detrimental impact on human health, in particular for women and seniors. Globally, more than 5 million people die each year because of excessive temperatures. High temperatures also tax energy supply as people turn to air conditioning to stay cool and save lives. The weather service urges people in hot locales to stay in air-conditioned spaces or find places to cool down.

Elsewhere in the US, deadly flooding swept through the lower Hudson River Valley north of New York City Monday, as a slow-moving weather front makes its way through the US Northeast. As much as 8.1 inches (20.6 cm) of rain fell at the US Military Academy at West Point through 6 a.m., following a flash flood emergency over the weekend. At least one person died, according to the Associated Press, with social media showing many roads were flooded or blocked by debris.