NEW YORK (NYTIMES) - Much of western United States is facing further record-breaking temperatures over the coming days with more than 31 million people in areas under excessive heat warnings or heat advisories. It is the third heatwave to sweep the region this summer.
In California's Death Valley, temperatures soared to 54.4 deg C on both Friday (July 9) and Saturday and was forecast to hit the same peak on Sunday.
The extreme temperatures that scorched the Pacific Northwest in late June led to nearly 200 deaths in Oregon and Washington, as people struggled to keep cool in poorly air-conditioned homes, on the street, and in fields and warehouses.
The same "heat dome" effect that enveloped the Northwest - in which hot, dry ground traps heat and accelerates rising temperatures - has descended on California and parts of the Southwest this weekend.
Ms Sarah Rogowski, a meteorologist with the National Weather Service, said daytime highs between 38 to 49 deg C were hitting parts of California. Most dangerously, temperatures will remain high into the night.
The record-shattering temperatures in the Pacific Northwest last week would have been all but impossible without climate change, according to researchers. Because climate change has raised baseline temperatures about 1 deg C on average since 1900, heatwaves are likely to be hotter and deadlier than those in past centuries, scientists said.
Excessive-heat warnings blanket most of California, along with parts of Nevada, Arizona, Utah, Oregon and Idaho.
California is facing the most extreme and widespread high temperatures. The agency that runs the state's electrical grid issued pleas on Thursday for consumers to cut back on power use to help prevent blackouts. Governor Gavin Newsom asked residents to cut their water consumption as he expanded a regional drought emergency.
The city of Merced reached 43.9 deg C on Saturday, breaking the record of 42.2 deg C set in 1961. Records could be broken this weekend in Fresno, Madera, Hanford and Bakersfield.
Cities and towns across the state's Central Valley activated cooling centres and temporary housing on Friday. Sacramento opened three cooling centres and provided motel vouchers to families with small children and older people who had no regular housing.
