September 24, 2023

People watch the sunset as a child drinks from a bottle of water on June 15, 2021 in Los Angeles, California as temperatures soar in a heat wave at the beginning of the season.

Frederic J. Brown | AFP | Getty Images

An extreme heat wave sweeping the western United States is set to intensify and spread this week, creating dangerous conditions amid the worst drought in two decades, and raising concerns about major forest fires and power outages.

More than 40 million people in the country are expected to see triple-digit temperatures this week, and about 200 million people are expected to experience temperatures above 90 degrees Fahrenheit. Severe drought has hit more than three-quarters of the west, according to the US Drought Monitor.

Temperatures in some areas could exceed 120 degrees and there are excessive heat warnings for several states. Record temperatures of 125 and 128 degrees are forecast in Nevada and Arizona.

Grant Poppy from Las Vegas tries to fry an egg in the parking lot at Badwater Basin, the lowest point in North America at 279 feet below sea level, in Death Valley National Park, California, on August 17, 2020.

David Becker | Reuters

Rupa Basu, director of air and climate epidemiology for the California Department of Environmental Impact Assessment, said the drought and heatwave created a “perfect storm” for fires and poor air quality.

Temperatures are expected to stay high overnight this week as well, a trend that will become more common with climate change as global temperature increases are not steady.

“Heat waves are exacerbated by the steroids of climate change and will break records more and more,” said Alexander Gershunov, a research meteorologist at the Scripps Institution of Oceanography at UC San Diego.

Heat waves also get more humid, which is dangerous because hot, saturated air makes it harder for people to cool off. Moisture is also likely to produce more thunderstorms, Gershunov said, which increases the likelihood of lightning strikes that start fires.

Lower nighttime temperatures that usually provide relief from hot days are disappearing, creating a dangerous combination of high daytime and nighttime temperatures that leave people unable to cool off at night.

The two Arizona Intake Towers will be shown on June 15, 2021 at Hoover Dam in Lake Mead National Recreation Area, Arizona.

Ethan Miller | Getty Images

“Saving energy during peak hours, avoiding excessive time outdoors, especially during strenuous activities or sports, drinking plenty of water, going for a walk [or] Bicycle instead of using cars for transportation, “Basu said.

High temperatures in air-conditioned rooms can lead to power failures and endanger people who cannot escape the heat.

Network operators in Texas and California have urged residents to limit their electricity usage to avoid blackouts this week. In Texas, high temperatures have already created a number of mechanical problems in power plants – just four months after a deadly winter storm killed millions of people.

Dry cracked earth can be seen along the shores of Phoenix Lake on April 21, 2021 in Ross, California.

Justin Sullivan | Getty Images

Due to the hot and dry temperatures and the high supply of dry undergrowth, forest fires also ignited at the beginning of this year. As of Wednesday, 33 major fires in 10 states had burned more than 360,000 acres, according to the National Interagency Fire Center.

Globally, every decade of the last half century has been warmer than the last, and 2020, at 2016, is the hottest year on record.

Global warming has also sent the US southwest into a decades-long mega-drought that has resulted in, among other things, a decline in snow cover, lake and river levels, and groundwater availability.