Nevada's heat wave that has kept temperatures above average since the middle of the month will break by the weekend, according to the National Weather Service in Reno.
While more than 50 people have died in California, Carson City residents have seen warm daytime temperatures at only a few degrees above average, but have been sweating through the nights.
"You've probably been noticing it more at night," said Mark Deutschendorf with the weather service. "It hasn't cooled as much as it tends to do."
Average nightly lows for Carson City, usually in the high 50s, have been staying in the mid- to upper-60s.
Carson City has set no record highs, but did tie with 1959 for the highest nighttime low, 69, on Sunday.
The average high for Eagle Valley is 91; temperatures instead have been registering in the upper 90s.
"We should start to notice some cooling by Saturday, it will be even more noticeable by Sunday or Monday. It should be in the upper 80s by Sunday, so get your jacket out. Lows should also be back in the 50s," Deutschendorf said. "We'll have to ride out these next few days, which will still be pretty hot.
"The end is in sight, and I'm not saying September either," he said
Gripped by a 10th straight day of 100-degree heat, California sweated out the possibility of more blackouts Tuesday as the number of suspected heat-related deaths climbed to at least 56 and the rotting carcasses of thousands of dairy cows and other livestock baked in the sun.
Some communities faced their third day without electricity as the record-breaking temperatures strained transmission equipment.
"We're asking people for one more day of conservation," said Gregg Fishman, the California Independent System Operator, which manages the power grid. "We're not out of the woods yet."
The stretch of 100-plus degree scorchers that descended on the state last week marks the first time in 57 years that both Northern and Southern California have experienced extended heat waves simultaneously, California Undersecretary for Energy Affairs Joe Desmond said.
In the Central Valley, where most of the deaths have occurred, temperatures hovered between 100 and 105 degrees Tuesday, down from 110 to 115 in previous days. Truly cooler weather was not expected until Wednesday.
Coroners in 14 counties were investigating deaths that appeared heat-related. Most of the victims were elderly. Among the dead was a nursing home patient in Stockton who died after the air conditioning gave out in 115-degree weather. A gardener collapsed on the job and died. A woman was found dead along a bike path.
On Tuesday, three elderly residents of single-room hotels within four blocks of the state Capitol were found dead. The rooms had no air conditioning.
The heat has been hard on livestock as well, causing thousands of deaths and a dip in milk production in California, the No. 1 dairy state, according to agriculture officials.
In the San Joaquin Valley, a combination of the searing heat, bigger dairies and fewer plants to dispose of dead animals created a backlog of rotting carcasses.
Tens of thousands of customers in Northern and Southern California had no electricity. About 1,700 San Jose customers faced their third day without power, and some residents slept in backyards and hotel rooms to escape the stifling heat.
Pacific Gas & Electric spokesman Brian Swanson said most outages were caused by equipment failures and not a shortage of electricity.
In Los Angeles, about 26,000 people were in the dark Tuesday evening as crews scrambled to fix hundreds of blown transformers, said a spokeswoman for the city Department of Water and Power.
The state's power consumption peaked Tuesday afternoon at 49,762 megawatts, shy of the record 50,270 megawatts set Monday.
Around the U.S.
In St. Louis, about 145,000 homes and businesses still without power after two storms last week knocked out electricity to nearly 600,000 customers. A utility worker was electrocuted Tuesday and another was injured while trying to restore power.
In New York City, a blackout that left about 100,000 people without electricity during some of the hottest days of the year all but ended Tuesday, allowing weary residents who endured nine days of rotting food and sweltering homes to begin getting back to normal.
Consolidated Edison said fewer than 500 people remained without electricity in the borough of Queens as of Tuesday.
A 51-year-old woman collapsed and died of heat stroke Monday while walking near her home in Lindsay, Okla., authorities said Tuesday. The temperature there had reached 95 degrees, and the woman's body temperature was 112.
- Associated Press Writers Marcus Wohlsen, Kim Curtis, Rachel Konrad and Juliana Barbassa in San Francisco, Olivia Munoz in Fresno and Samantha Young and Robin Hindery in Sacramento contributed to this report.