California has been baking under scorching conditions with temperatures reaching a record 49 Celsius (120 Fahrenheit) on Sunday in Woodland Hills, an all-time high for Los Angeles County, the National Weather Service said.

With the hot and dry conditions, California has suffered a particularly busy fire season this year, with more than 1.6 million acres (647,497 hectares) destroyed so far, including in three of the biggest blazes in the state’s history.

More than 500 firefighters and four helicopters were battling the El Dorado blaze east of San Bernardino, which started Saturday morning, California Department of Forestry and Fire Protection (Cal Fire) said.

Officials have blamed a gender-reveal party for sparking the El Dorado Fire with “a smoke generating pyrotechnic device”.

In northern California, more than 200 people were airlifted to safety by military helicopters during the weekend after a fast-moving wildfire trapped them near the Mammoth Pool Reservoir northeast of Fresno.

The Creek Fire, which started on Friday in steep and rugged terrain, has so far spread to 73,000 acres (29,542 hectares), according to the US Forest Service, making it one of the largest.

More than 800 firefighters were battling the blaze.

Another rapidly spreading fire near San Diego, Valley Fire, has so far spread to 10,000 acres (4,047 hectares) and destroyed 11 structures, Cal Fire said.

California governor Gavin Newsom on Sunday declared a state of emergency for five counties affected by the Creek, El Dorado and Valley fires.

“The fires have burned tens of thousands of acres, destroyed homes and caused the evacuation of thousands of residents,” the governor’s office said.

Record temperatures during the three-day Labor Day weekend have aggravated already dangerous fire conditions and further stressed exhausted California firefighters.