LOS ANGELES — While people in some parts of the country are watching the leaves turn a kaleidoscope of fall colors as they contemplate unpacking winter clothes, California is roasting under an autumn heat wave.
As high temperatures were ranging from the low 100s in Southern California to the 90s in the normally cooler San Francisco Bay Area on Friday, National Weather Service forecasters warned it was just a warm-up for what lies ahead this weekend.
‘‘We’re looking for it to peak tomorrow,’’ said Stuart Seto of the National Weather Service, adding that some high-temperature records could fall Saturday. In the coastal city of Santa Maria, three hours north of Los Angeles, Friday’s 100-degree reading tied a record for the date set in 1985. Meanwhile, temperatures at San Francisco International Airport reached 95 degrees, beating a record of 94 set in 1985, according to the National Weather Service.
Forecasters blame the Santa Ana winds, those chameleon-like gusts that start out icy cold in the Great Basin region of Utah and Nevada, but by the time they race across deserts and down mountain canyons and arrive in Southern California they are hot as . . . well, you know.
Usually during a heat wave Southern Californians can tell themselves, ‘‘Well, it’s hotter in Arizona and Death Valley.’’ Not this time. By mid-afternoon Friday, it was 99 in Long Beach, the same as the temperature in Death Valley, Calif., which calls itself the hottest place on the planet. It was 95 in Phoenix.
The current heat is unusual but not unprecedented. Although temperatures for this time of year are normally in the high 70s, it reached 108 in Los Angeles on Oct. 3, 1987, and again the next day. ‘‘It’s hot but not record-breaking hot,’’ says Seto. Not yet, anyway. LA’s Woodland Hills neighborhood could surpass 108 degrees Saturday.
Los Angeles County has opened cooling centers at places like libraries and community centers. The Long Beach Unified School District sent its 76,000 students home an hour early on Thursday and Friday to get them out of class before the hottest part of the day.
The Los Angeles Department of Water and Power is urging people to set their air conditioning thermostats at 78 degrees. With wildfire danger high across much of the state, the Los Angeles County Fire Department has beefed up many of its firefighting crews from three to four people.
‘‘We’ve got wind, heat, the perfect combination, everything in alignment for a potential brushfire,’’ fire Captain Rich Moody said as he and his crew patrolled a Southern California hillside.