With more than 59 million people under various heat warnings Saturday, the hot weather was expected to simmer unabated for the next few days.
The sweltering weekend conditions impacted cities including Los Angeles, Seattle and Las Vegas in the West, and in Raleigh, North Carolina, Washington, D.C., and New York City in the East.
“A staunch upper ridge” has brought a “widespread and long duration heat wave” to the West, where temperature records may be tied or broken over the weekend, the weather service said. Temperatures in the high 90s to the 110s are likely along the coast and in parts of the Great Basin.
“These conditions will be extremely dangerous and potentially deadly if not taken seriously,” the service warned. “The multi-day nature of the heat and record warm overnight temperatures will cause heat stress to build in people without adequate cooling and hydration.”
An all-time record-breaking temperature of 124 degrees has already been reported Friday in Palm Springs, California, per the weather service field office in San Diego. The previous record was 123 degrees.
On Saturday, Death Valley set the record high for the date with a reading of 128, the weather service said. The previous high mark for the date happened in 2007, when the reading reached 127.
Las Vegas tied its record high temperature for the date when it reached 115 degrees on Saturday, the weather service said. Reno, Nevada’s high of 105 represented a “shattering” of the previous July 6 record high set in 2014, the weather service office in Reno said.
Phoenix appeared to come one degree short of tying its record high for the date, 116, by posting a preliminary high of 115, according to weather service data.
Record high temperatures in Las Vegas; Reno, Nevada; Portland, Oregon; Tucson, Arizona; Orlando; and El Paso, Texas continued to be possible on Sunday, forecasters said.
Excessive heat watches, warnings and heat advisories have been issued for much of the West throughout the weekend and even into next week.
Oregon Gov. Tina Kotek declared an extreme heat emergency Friday because of high temperatures forecast for the state through Tuesday.
“Both the record-breaking temperatures and the duration of heat present a clear and present danger, particularly for children, elders, people with disabilities, and people who work outside,” Kotek said in a statement. “I am urging Oregonians to take every precaution and check on your family and neighbors.”
In Arizona, temperatures as high as 115 are expected in Phoenix and Yuma over the weekend going into next week, according to the weather service field office in Phoenix.
The intense heat combined with dry and windy conditions will also “support a Critical Risk of Fires” in parts of southern Idaho on Saturday and southern Utah on Sunday, according to the weather service.
On the East Coast, temps will range 5 to 10 degrees above average, with highs in the 80s and 90s. Factoring in the humidity, it will feel more like 100 to 111 degrees through Saturday afternoon.
Some improvement is expected Sunday in the mid-Atlantic region, with 100- to 110-degree heat index values remaining across the Gulf Coast and Southeast. The heat index value is what temperatures feel like to the human body.
Heat advisories have been issued on the East Coast from New York down to the Alabama coast, including Charleston, South Carolina, where heat index values up to 112 are possible, and the New York City metro area, where it could feel like around 100 degrees.
In New York, libraries and community centers were converted to “cooling centers” where members of the public can go to stay cool.
Newark, New Jersey, Mayor Ras J. Baraka issued an excessive heat advisory for the weekend as temperatures are expected to rise above 90. The city warned residents to take precautions to prevent heat-related illnesses by staying cool and hydrated.