Brian Nieuwenhuis, a meteorologist with the National Weather Service in Medford, Oregon, said there was also a risk that too much rain could spill debris or mudslides, which could pose a danger to firefighters.
While the conditions had somewhat resolved, he added, “fire activity should continue throughout the week.”
The fire, which remained zero percent under control Tuesday, is one of 60 major wildfires and fire complexes that have burned more than 1.6 million acres in the United States so far this year, according to the National Interagency Fire Center. In Siskiyou County, the China 2 and Alex fires, which along with the surrounding lightning fires are known as the Yeti complex, have burned more than 2,400 acres, authorities said.
The McKinney fire comes at a precarious time for the state, which, along with the Pacific Northwest, experienced abnormally high temperatures last week as a heat wave blanketed the region.
Days of scorching temperatures and drought have contributed to the intensity of fires by making vegetation drier and more likely to ignite. Analyzes have shown that human-induced climate change has increased the likelihood of such extreme heat waves.
Siskiyou County is in extreme drought, according to the US drought monitor. Drought stress can kill trees, said meteorologist Mr. Nieuwenhuis.
“You kill a tree,” he added, “and it just turns into a big chunk of firewood.”