"This is a climate signal," Mr. Carbin said.
There were six heat deaths within 10 days earlier this month in Riverside County, which extends from about 70 miles east of the coast to the Arizona border.
"We can not remember seeing such a section," said Jose Arballo, a spokesman for the district health department, adding that the cities in the western part of the district had been at temperatures over 115 degrees Celsius for days. "We see the next heat over longer periods of time – when it gets cold, we will still be in the 90s and we would not be surprised if we see more deaths."
The Weather Connected The Yosemite's rugged terrain also makes it difficult for firefighters to defend themselves against the fire.
"The conditions are unbelievably tiring and we are seeing partial three-digit temperatures and some sections are extremely remote," said Dan McKeague, a spokesman for the United States Forest Service. "Access is limited because there are not many roads, the standing dead trees will fall, and that represents a great risk."
In Jackson County, Oregon, Julie Denney said that the lightning storm that opened the fire a little more than a week ago, most in her memory, and the weirdness that comes early in the day around 9 in the morning. Summer flashes in the west are a regular afternoon phenomenon when the heat builds up and suddenly breaks into violent redemption.
But on this sultry, oppressive morning in the county and neighboring Josephine County, about 115 fires began that were associated with this particular storm, and on Wednesday burned three major fires, including the Garner Complex in Josephine and Jackson Counties. The fire had burned nearly 20,000 acres with more than 2,400 fighting people, and contained only 18 percent.