Introduction to the Heat Wave
The season’s most dangerous heat wave is expected to bake Southern California and much of the American Southwest this week, with triple-digit highs and elevated fire conditions set to begin Wednesday and last for several days.
Expected Temperatures and Conditions
Extreme heat and fire weather advisories have been issued for much of inland Southern California, with peak temperatures expected Thursday and Friday. Downtown Los Angeles is forecast to reach 94 degrees, while Woodland Hills could hit 108. Los Angeles County valleys and the Inland Empire will likely heat up to 104 degrees. Palm Springs could hit above 113 and Death Valley is bracing for 120 degrees, according to the National Weather Service.
Meteorologist’s Warning
“This is going to be the most significant heat wave of the season so far,” said Ariel Cohen, the meteorologist in charge at the weather service’s Oxnard office. “We’re going to be having a once-a-year, once-every-other-year-caliber heat wave. … Everyone needs to be getting prepared now.”
Twitter Alert
Temps are trending up for the latter half of the week, and the heat + elevated fire weather conditions will continue through the weekend. Consider changing outdoor activities, and review fire evacuation plans (esp. mountain and valley residents). Stay safe!🌞🔥#CAwx #LAweather pic.twitter.com/5LurV2g5kn
— NWS Los Angeles (@NWSLosAngeles) August 17, 2025
## Precautions and Safety Measures
While this is typically the hottest time of year, he said, highs at the end of the week will reach near records, 10 to 20 degrees above normal. People need to stay hydrated, make sure they have access to air conditioning and refrain from outside activities in the heat of the day in order to avoid heat illness, Cohen said.
### Weather Service Warning
“The most impactful heat and fire weather concerns will pick up Wednesday through Sunday,” the weather service warned. “Consider reassessing outdoor plans for that time, stay hydrated, and be careful with anything that can spark a fire.”
## Cause of the Heat Wave
The high-pressure system driving this heat wave will not only persist over the region for a prolonged period, but is also expected to be “stronger than normal,” said Kristan Lund, another weather service meteorologist in Oxnard.
### Duration of the Heat Wave
“This high pressure is sitting out over us for a long duration,” Lund said. “We could see temperatures still elevated for this time of year … into early next week.”
## Overnight Temperatures and Concerns
The system’s length and strength will be compounded by some offshore winds, which will help keep any marine influence at bay and keep temperatures high, even overnight.
### Vulnerable Populations
Lund said much of Los Angeles could remain in the 70s overnight Thursday, which is particularly concerning for sensitive populations — such as elderly people, those who are pregnant or laborors working outdoors — who can be more vulnerable to heat illness without time to recover at night.
## Extreme Heat Watch
An extreme heat watch has been issued for Wednesday through Saturday across the region, with highs up to 106 possible across the Los Angeles County valleys, the Ventura County valleys, the San Luis Obispo County valleys and mountains, the Santa Barbara County mountains and San Bernardino County deserts.
### Regional Temperature Expectations
The Riverside, San Bernardino and San Diego County mountains could see highs up to 99 degrees Thursday and Friday, while the Inland Empire is forecast to reach up to 104 degrees.
## Fire Concerns
In and around Death Valley, where highs are expected up to 120 degrees, officials warn that “above normal daytime temperatures combined with minimal overnight relief from the heat” could increase the threat for heat-related illness.
### Fire Weather Watch
A fire weather watch, which signals that critical fire weather is expected, has been issued from Wednesday through Saturday for much of the Los Angeles and Ventura County mountains and foothills, warning that the “unseasonably hot and unstable air mass [is] capable of producing explosive fire behavior.”
## Conclusion
The upcoming heat wave is expected to be the most significant of the season, with extreme temperatures and fire conditions posing a significant threat to the region. It is essential for residents to take necessary precautions, stay hydrated, and be prepared for potential evacuations.
## FAQs
Q: What are the expected temperatures during the heat wave?
A: Temperatures are expected to reach up to 120 degrees in Death Valley, 108 in Woodland Hills, and 94 in Downtown Los Angeles.
Q: What precautions should people take during the heat wave?
A: People should stay hydrated, avoid outside activities during the heat of the day, and have access to air conditioning to avoid heat illness.
Q: Are there any fire concerns during the heat wave?
A: Yes, the heat wave is expected to create exceptional fire weather, with a fire weather watch issued for much of the Los Angeles and Ventura County mountains and foothills.
Q: How long is the heat wave expected to last?
A: The heat wave is expected to last from Wednesday to Saturday, with temperatures potentially remaining elevated into early next week.
