A significant heat wave is set to hit inland Southern California this week, with temperatures in some areas expected to soar into triple digits, prompting health concerns and raising the threat of wildfires.
According to the National Weather Service, parts of the San Fernando Valley, deserts in Los Angeles County, and the Inland Empire could see temperatures reach the high 90s on Tuesday.
The Coachella Valley could face even more extreme conditions, with forecasts indicating highs around 114 degrees.
The worst of the heat is expected to occur on Wednesday and Thursday, with even broader areas experiencing triple-digit temperatures across the valleys and deserts.
“Big changes [are] coming … as high pressure over Arizona expands west into Southern California,” the weather service noted in its Monday night forecast for Los Angeles.
A strengthening high-pressure system will quiet onshore winds and bring warmer conditions, pushing the marine layer down to under 1,000 feet by Wednesday.
This shift is anticipated to cause significant warming in inland regions while affecting coastal areas only slightly.
Additionally, this heat wave will lower afternoon humidity levels and further dry an already parched landscape, creating conditions ripe for wildfires.
As Casey Oswant, a meteorologist with the National Weather Service in San Diego, pointed out, “The hot, dry conditions do make the area a little more prone to fire starts.”
On Monday, three small brush fires ignited across various locations in Riverside County, which has already faced numerous wildfires in recent weeks.
Maggie Cline De La Rosa, a spokesperson for both the California Department of Forestry and Fire Protection and the Riverside County Fire Department, confirmed, “It has been very busy. We do expect that to continue because we have a heat wave coming, and we do have a lot of dry vegetation.”
Despite these challenges, first responders are prepared for the increased risk.
“We’ve been prepared; we remain prepared,” Cline De La Rosa stated.
On Monday night, firefighters tackled a fire in Jurupa Valley that initially spanned about 45 acres but remained mostly in a rural area.
By Tuesday morning, the Pyrite fire was reported to be 50% contained.
Earlier the same day, another blaze named the Nichols fire erupted near Interstate 15 close to Lake Elsinore, briefly closing a lane of the highway as it grew to about 50 acres.
However, by Tuesday morning, it was 98% contained.
A third fire near Banning reached approximately 13 acres and was fully contained by the end of the day.
This heat wave is not only raising temperatures but is also expected to degrade air quality throughout inland Southern California, leading to what officials classify as a “multiday extreme ozone [smog] event.”
High temperatures combined with stagnant air will trap air pollutants in the basin, creating potential health hazards for vulnerable populations and possibly leading to universally unhealthy air in the Inland Empire and desert regions, according to the South Coast Air Quality Management District.
In Los Angeles County, the most severe heat this week is predicted for the San Fernando Valley, Antelope Valley, and Santa Clarita Valley, where temperatures are forecast to linger in the 90s and may reach triple digits.
Residents in downtown and East Los Angeles can expect highs in the 80s to around 90, while coastal areas will generally stay in the 70s.
The Inland Empire is expected to see particularly extreme conditions, leading to a heat advisory that will cover much of San Bernardino and Riverside counties from 10 a.m. on Wednesday until 8 p.m. on Thursday.
Cities under this advisory include Corona, Moreno Valley, Ontario, Rancho Cucamonga, Riverside, San Bernardino, and Fontana, with predicted temperatures ranging between 97 and 104 degrees.
Inland areas of San Diego County will also be under a heat advisory during the same period, including the communities of San Marcos, El Cajon, La Mesa, Escondido, Poway, and Santee.
Officials advise residents in these areas to stay hydrated, remain indoors in air-conditioned spaces, avoid direct sunlight, and check on family and neighbors.
While the heat in Los Angeles is projected to remain below heat advisory levels—partly due to relatively cool overnight temperatures in the low to mid-60s—Angelenos are still advised to refrain from engaging in strenuous outdoor activities and to be aware of potential heat-related illnesses this week.
The heat wave is expected to ease after Friday as the high-pressure system begins to weaken, bringing a return of ocean breezes and cooler temperatures.
More widespread relief is anticipated over the weekend, with temperatures expected to fall back to seasonal averages.
However, forecasts indicate that another heat wave, potentially more intense and coupled with gusty onshore winds, may arise next week.
image source from：latimes
