A National Weather Service heat advisory ran down the Central Valley, through inland Southern California and into Nevada. An excessive heat warning extended eastwards across the desert to Nevada.
Because of the expected high demand for air conditioners, the state energy grid operator requested voluntary conservation of electricity between 4-9 p.m.
Due to the possibility of lightning strikes and thunderstorms, a fire weather watch has been issued in Northern California for Thursday night through Friday evening.
Forecasters stated that "the combination of potential dry lightning and strong winds with dry fuels could result in critical fire weather conditions."
The second-largest wildfire in California history, which has burned nearly 1,441 square mile (3,732 kilometers) in the southern Sierra Nevada and southern Cascades regions, was located in the northern Sierra Nevada. The Dixie Fire was 59% contained, and evacuation warnings were lifted for some areas in Plumas and Lassen counties. More than 1,280 structures were destroyed, including 688 homes.
To the south in the Sierra near Lake Tahoe, the nearly 340-square-mile (880-square-kilometer) Caldor Fire remained 50% contained. The state's 15th largest fire has been contained by firefighters to the point that South Lake Tahoe residents were allowed to return home. Nearly 1,000 structures, including 776 single-family houses, have been destroyed after inspections were completed at 95%.
Caesars Entertainment Inc., the owner of Harrah's Lake Tahoe, said that the hotel began to reopen in stages. It started with guest bookings on Wednesday and ended on Thursday for table games. According to the company, Harveys Lake Tahoe casino will be reopen on September 17 for table and slot games and hotel bookings on September 18.
The 18th largest fire in the state has destroyed nearly 296 miles (767 kilometers) of Shasta-Trinity National Forest, which is located in the mountains on the north coast. Although the Monument Fire was contained at 41%, it posed a threat to over 10,500 structures.
California has seen wildfires that are more severe and deadly in recent years. This is because the U.S. West has become much warmer and dryer over the last 30 years. Scientists predict that wildfires will be more destructive, unpredictable, and more extreme in the future.