A brush fire that broke out next to the 15 Freeway in the Cajon Pass grew to 100 acres Friday morning and forced lane closures on the route between Southern California and Las Vegas.
The fire spread from a box truck to an embankment and hillside next to the freeway near the Kenwood Avenue exit, according to the San Bernardino County Fire Department.
There were no reports of injuries or structure damage. Two northbound 15 Freeway lanes were closed.
In July 2015, a fire in the Cajon Pass torched vehicles on the freeway, forcing drivers and passengers to abandon their cars and seek protection as flames raced across the road.
Friday's fire started during the warmest day of 2018 and Southern California's first heat wave of summer. Temperatures are expected to break records Friday and remain near and above triple-digits this weekend.
The small fire is the latest in what has been an active early summer for firefighters. Cal Fire has reported more than 2,600 wildfires since the start of the year. Last year, the agency reports 2,300 fire during the same period.
Last year was one of the most deadly and destructive on record in terms of wildfires in California. Forty-six people were killed and more than 11,000 homes were destroyed by wildfires in 2017. More than 9,000 fires burned 1.2 million acres across California.
The significant increase in the numbers and size of fires last year was largely because the state was coming off one of its wettest winters in years in 2016-2017, which left hillsides covered in grass and other vegetation. That grass dried out in summer and turned into tinder, providing fuel for rapidly spreading fires often pushed by strong winds that can carry hot embers for miles and turn small spot fires into infernos.
An increase in the number of dead and dying trees also has exacerbated the wildfire threat, Cal Fire officials said.
Since 1970, California is not only seeing more fires, but larger fires. Seven of the top 10 largest have all occurred since 2000.