California’s ‘dangerous’ heat wave adds to challenge firefighters face battling River Fire
High temperatures and an ample supply of grass and brush dried out by drought are combining to create problems for crews battling to contain the River Fire burning in the Sierra Nevada foothills southwest of Yosemite National Park.
The fire began Sunday afternoon south of Mariposa, where afternoon highs reached 107 degrees in the early hours of the blaze. By Sunday night, the fire’s size was estimated at more than 4,000 acres, and containment was estimated at 5%.
On Monday afternoon, the acreage estimate had grown to 8,000 acres with 10% containment.
“The weather has been extremely hot and dry, and the humidity is very low,” Jaime Williams, a Cal Fire public information officer, told The Bee on Monday. “There has been tree torching and wind-driven runs and spot fires, and it’s all very challenging for firefighters.”
By mid-afternoon Monday, temperatures in Mariposa had reached 103 degrees, the National Weather Service reported.
“Firefighters continue to aggressively attack the fire while dangerous heat persists,” Cal Fire reported on the incident page for the River Fire. “Extreme fire behavior due to low fuel moisture and persistent drought is a concern.”
The heat wave that has hammered Fresno and the central San Joaquin Valley also poses a very real danger to firefighters laboring in their protective wildland fire gear. As of Monday morning, almost 480 people were involved in the effort.
Crews could see some slight relief from the triple-digit temperatures over the next couple of days. The National Weather Service forecast for Mariposa calls for a high of 98 degrees on Tuesday, 95 degrees on Wednesday, and 91 degrees on Thursday, with overnight lows between the mid-70s and mid-60s.
This story was originally published July 12, 2021 at 4:07 PM.
