While wildfires occur throughout the West every year, scientists see the influence of climate change in the extreme heat waves that have contributed to the intensity of fires this summer. Prolonged periods of abnormally high temperatures are a signal of a shifting climate, they say.

The 175,000-acre Carr Fire in Northern California, which remains just 48 percent contained, has wreaked havoc on Shasta County and the town of Redding. At one point the blaze prompted nearly 40,000 evacuations and has burned more than 1,000 homes to become the sixth most destructive fire in the state’s history.

The Mendocino Complex Fire, about 100 miles north of San Francisco, has burned more than 300,000 acres and, just 50 percent contained, is already the largest wildfire in the state’s history. The Ferguson Fire in Mariposa County near Yosemite National Park has led to the continued closing of Yosemite Valley. Ten people have died from the fires in the last four weeks.

The Holy Jim Fire is smaller than those blazes but has threatened thousands of homes in an area. What started as a small fire in the Holy Jim Canyon area has exploded in size, growing overnight Thursday to 9,600 acres from 6,200 acres a day earlier. Hot temperatures in the area and very low humidity have exacerbated the fire, which nearly 700 fire service workers are involved in fighting.

The fire has spilled over the Orange County line into Riverside County.

Footage of Mr. Clark being arrested captured by a local CBS affiliate station showed him standing outside his home shirtless and in handcuffs, while the other homes around his burned. At one point during the arrest, Mr. Clark began stripping the rest of his clothing, which was also captured in news photographs.