As blazes rage on, worst fire weather of season is ahead for California and much of western US

By Alex Sosnowski, AccuWeather senior meteorologist
July 12, 2018, 8:05:05 PM EDT

While the North American monsoon has gotten underway in the western United States, fire season will continue in California and in many other areas through the summer.

For much of the West, fire season continues to ramp up during July and reaches a peak in August.

"Most of the time during the summer, heat, strong sunshine and progressively drying fuels cause fire conditions to get worse from day to day," according to AccuWeather Meteorologist Evan Duffey.

Static Fires 3 pm

"On your good days, fire conditions just don't get worse," Duffey, who is also a volunteer firefighter, said.

Moisture from the monsoon can make some fuels more moist and fire ignition more difficult. However, strong winds often extend miles away from a thunderstorm that might produce rain in a small area. These winds can create havoc for those fighting existing fires.

While human activity, such as campfires, burning of debris, discarded cigarettes and arson, are the leading cause of wildfires, lightning is main natural cause of ignition, according to the National Park Service.

The average lightning bolt is 54,000 F, which is several times hotter than the surface of the sun. So a storm producing little to no rain can lead to a raging fire in a matter of minutes.

The most common ways people spark devastating wildfires in the US
Photos: Blinding haboobs, flooding and power outages hit Phoenix, Las Vegas
Monsoon storms to be double-edged sword in southwestern US into the weekend

The largest active fire in the U.S. is the Martin Fire, near Winnemucca, Nevada. The predominantly grassland fire has grown to more than 435,000 acres as of Thursday afternoon, according to Inciweb.

"During the afternoon, stiff breezes will cause the Martin Fire to move along between 10 and 12 mph," according to Duffey. "A fire moving at that speed is faster than a person can run, so boots-on-the-ground attempts to contain a fire of that nature must be done cautiously to keep firefighters away from the fast advancing fire front."

Another fire in Nevada, called the Hogan Fire had burned 11,000 acres and was 60 percent contained as of Wednesday, according to Inciweb.

The largest active fire in California and the largest of the season so far is the County Fire. This fire is located in Napa and Yolo counties.

AP County Fire

Flames rise around an outbuilding as the County fire burns in Guinda, California, Sunday July 1, 2018. At times smoke has reached some 75 miles to the south and the San Francisco Bay Area. (AP Photo/Noah Berger)

The County Fire has consumed more than 90,000 acres and was 89 percent contained as of Wednesday night, according to Cal Fire. Twenty structures have burned in the fire. Steep terrain has been a challenge in fighting the blaze. All evacuations have been lifted for the Country Fire.

The Klamathon Fire, burning in Siskyou County, Northern California, has spread into neighboring Oregon and taken one civilian life and injured three firefighters thus far. Evacuation orders have been given for Copco Lake area of California.

Static AP Klamathon Fire

In this photo released Friday, July 6, 2018, the Klamathon Fire burns in Hornbrook, California. The fire burned swiftly through the rural area, which is home to many retirees. The blaze reached Hornbrook, a community of about 250 people about 14 miles south of the Oregon border. Authorities said one person was killed in the fire. (California Highway Patrol / AP)

The Klamathon Fire has consumed 36,500 acres, has burned 82 structure and threatens more than 300 others, including homes and businesses. This fire was 70 percent contained as of Thursday morning.

In Southern California, the Valley Fire, in San Bernardino County, has burned 1,348 acres thus far and was only 24 percent contained.

Meanwhile, some smaller fires erupted in California early this week.

The Hale Fire broke out in Morgan Hill, Santa Clara County, and quickly consumed 50 acres on Tuesday. Four horse perished in the fire and multiple buildings burned.

A fire broke out near the Griffith Park Observatory and the iconic Hollywood sign in the Los Angeles area on Tuesday. While no structures were threatened, the small fire consumed 10 acres. Multiple vehicles were damaged or destroyed.

Building heat in the Northwest will increase the risk of wildfire ignition and spread in the coming days.

"In the northwestern U.S. and in some areas of the interior West in general, fire season winds down in the autumn as storms with more substantial rain and high-country snow move in from the Pacific Ocean," Duffey said.

In parts of the West, such as in Southern California, wildfire season continues beyond the summer and peaks during the autumn as the monsoon diminishes and Santa Ana winds play a significant role.

These strong winds that blow out of the mountains and through the canyons and on toward the Pacific coast can be strong enough to knock down trees and power lines, which can spark fires.

Storms that begin to frequent the Northwest often fail to bring much rain to Southern California until the winter.

Episodes of Santa Ana winds can occur through the winter in Southern California.

Meanwhile, in Alaska, cooler air, showery conditions and higher humidity levels are likely to slow the spread of existing fires and reduce the chance of new blazes igniting this week.

Approximately 66 wildfires were active as of July 12, according to the Alaska Interagency Fire Center. The fire season has been a bit below average thus far.

Peak fire months, on average, are June and July in Alaska. Temperatures trend downward significantly during August and September, which tends to inhibit wildfire ignition, depending on the weather patterns.

Report a Typo


Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.

More Weather News