A firefighting helicopter makes a water drop as the Holy Fire burns near homes on August 9, 2018 in Lake Elsinore, California. The fire continues to grow amidst a heat wave and has now burned 10,236 acres while remaining just five percent contained.

At least 13 large fires raged across California on Friday, threatening over 16,000 homes and leading to evacuation orders for nearly 25,000 residents in what is shaping up to be one of the worst fire seasons on record in the state.

The surge in fire activity has led California to call for help to at least 17 other states and two countries. The state also has received assistance from the military, including active-duty troops and aircraft to assist in dropping water and retardant.

California already has spent $230 million on emergency firefighting since the start of the July 1 fiscal year, according to Cal Fire. That is more than half the state's $442.8 million annual so-called e-fund budget.

"In terms of acres burned so far this year, we're well over last year's numbers," Heather Williams, a spokeswoman for California Department of Forestry and Fire Protection, or Cal Fire, told CNBC. "We're definitely seeing the same continued trend that we saw in 2017, which is larger fires burning very quickly, causing evacuations quite early and burning in very populated areas as well as impacting multiple counties."

Williams said extreme heat and dry conditions coupled with no shortage of vegetation fuels on the ground is exacerbating the risks of wildfires. There's also an estimated 129 million dead trees in California, most of it in the central and southern Sierras.

Nearly 14,000 firefighters are on the lines of fires statewide as well as several hundred active-duty military troops. There also have been dozens of military aircraft used in the recent California fires as well as a large 747 passenger plane converted to carry more than 19,000 gallons of fire retardant.

The Boeing 747 plane dubbed the SuperTanker was put into service for retardant drops this week on fires burning in both the southern and northern portions of the state. It is contracted on a "call when needed" basis by Cal Fire and can cost more than $16,500 per flight hour.

If the state exhausts its e-fund firefighting budget in fiscal 2018-19, it could tap other sources such as traditional budget reserves. Those reserves now total about $2 billion.