A heat wave blanketing Southern California is driving blistering temperatures from the beaches to the mountains, triggering excessive-heat warnings and sparking fears that the hot, dry conditions are ripe for wildfires.
With temperatures expected to reach triple digits in some areas, the National Weather Service issued an excessive-heat warning from 10 a.m. Tuesday to 9 p.m. Friday in the mountains of Ventura and Los Angeles counties, not including the Santa Monica range.
The worst heat will probably bake the region Tuesday and Wednesday, with gradual cooling Thursday and into the weekend, said meteorologist David Sweet with the weather service's Oxnard office.
Searing temperatures are expected in the inland parts of Los Angeles County, with Santa Clarita and Woodland Hills likely to reach 109 degrees Wednesday and Lancaster 111.
The coastline will also see unusually hot conditions, with 86 degrees expected in Ventura and Malibu on Tuesday and 97 predicted for Long Beach.
Some of the hottest temperatures are expected in the low desert areas, including the Coachella Valley and Borrego Springs, which could see highs between 110 and 120 for an entire week.
Temperatures could break records, and will clock in about 10 to 20 degrees above what's typically recorded this time of year in some places, Alex Tardy, a meteorologist with the weather service's San Diego station, said in a recent briefing.
"This is unusual and much above average — in record territory — even for June," Tardy said.
At this time of year, the region is normally mired in a marine layer with clouds and fog dubbed "June gloom."
A combination of hot air overhead and northerly winds is causing the above-normal temperatures, Sweet said.
The winds are causing red flag conditions in southern Santa Barbara County, with gusts of 40 to 50 mph. And the low humidity, high heat and unseasonably dry fuels are creating an elevated fire risk, the weather service said.
Critically low moisture levels may have contributed to the eruption of the 400-acre Flats fire in the Santa Rosa Mountains on Sunday morning. The fire, which burned at least two homes, continues to threaten several mountain communities southwest of Palm Desert in Riverside County.
One firefighter was injured in the blaze, and officials are concerned the regional heat wave will complicate the fight to extinguish it.
“The main concern is going to be firefighter heat illness,” said Lisa Cox, a spokesperson for the San Bernardino National Forest.
Temperatures are expected to drop by the weekend, but some areas, including the mountains and deserts, might hang on to the heat wave longer, Tardy said.
Even when the heat recedes, the combination of intensely high temperatures and prolonged dryness will worsen California’s critical climate condition.
Six of the last 10 years have had below-average rainfall, according to the Los Angeles Almanac. The latest heat wave underpins California's increasingly dry environment, with a drought emergency blanketing 41 of the state's 58 counties.
“Early heat waves and more frequent heat waves this summer will exacerbate an already serious situation,” said climatologist Bill Patzert, noting that it is “way too early” in the year for such an event.
“It crosses many boundaries and really impacts everybody,” he said.
To stay cool in the coming days, officials say, people should drink plenty of fluids, stay in air-conditioned rooms or shade as much as possible and not leave children or pets unattended in vehicles.
Among other tips from the National Weather Service:
Check in with older relatives and neighbors.
Wear light-colored and loose-fitting clothing.
Reschedule strenuous activities to cooler hours in the morning and evening.
Many libraries, senior centers and community spaces around Los Angeles County are offering residents a free respite from the heat. Helen Chavez, associate director of the county's Office of Emergency Management, recommended that people find a cooling center near them and call to ensure the hours posted online are correct.
"If they don’t have a means of keeping cool, whether it’s at a relative's or a friend’s place or a place like a mall or movie theater ... there are great free community assets," Chavez said.
Most Los Angeles public pools are also opening just in time for the heat wave, with availability from 2 to 6 p.m. Tuesday through Friday and 1 to 5 p.m. Saturday and Sunday, the city's Department of Recreation and Parks announced.
Times staff writer Hayley Smith contributed to this report.
This story originally appeared in Los Angeles Times.