Much of San Diego County under heat advisory later this week. Here's where

Aug 5, 2025 - 00:00

SAN DIEGO (FOX 5/KUSI) — Much of inland San Diego County will be under a heat advisory later this week, while San Diego County desert areas will be under an extreme heat warning.

The National Weather Service has issued a heat advisory from 10 a.m. Wednesday to 8 p.m. Friday for San Diego County valley and mountain areas.

The heat will peak Wednesday into Thursday across Southern California and Southwest Arizona, with the hottest conditions expected on Thursday east of Interstate 15.

Temperatures are expected to reach 90 to 102 degrees in San Diego County valley and mountain areas, including Santee, Poway, La Mesa, San Marcos, Escondido, El Cajon, Pine Valley and Julian.

*The orange on the map shows much of inland San Diego County will be under a heat advisory Wednesday through Friday (PHOTO: National Weather Service)*

For the coastal areas: 73 to 82, western valleys and inland Orange County: 82 to 89, inland valleys: 88 to 98, mountains between 4000 ft and 7000 ft: 80 to 91, high desert: 95 to 102, low desert: 108 to 111 (PHOTO: National Weather Service)

For the coastal areas: 78 to 87, western valleys and inland Orange County: 87 to 95, inland valleys: 94 to 104, mountains between 4000 ft and 7000 ft: 84 to 95, high desert: 99 to 106, low desert: 114 to 117 (PHOTO: National Weather Service)

Warming conditions expected for the middle to end of next week. By Thursday widespread moderate HeatRisk is expected for the valleys, mountains and High Desert. Widespread major HeatRisk is expected for the low desert (PHOTO: National Weather Service)

At the same time, San Diego County and Imperial County deserts will be under an extreme heat warning from 10 a.m. Wednesday to 8 p.m. Friday, NWS reports. Temperatures are expected to reach 106 to 118 degrees in those areas.

Some reprieve from the heat wave -- the county has seen some cloudy, hazy conditions as satellite and radar showed smoke traveling south from the Gifford Fire burning in San Luis Obispo and Santa Barbara counties that is mixing with coastal cirrus clouds moving east from the Pacific Ocean to create the hazy conditions.

HeatRisk serves as another NWS tool that can be used to protect lives and property from the potential risks of excessive heat, being especially useful for those who are more easily affected by heat or those who provide support to those communities of heat-sensitive individuals. HeatRisk ensures that communities have the right information at the right time to be better prepared for upcoming heat events. HeatRisk has been available in the Western United States since 2014 and was expanded across the contiguous United States in 2024 (PHOTO: National Weather Service)

NWS forecasts Ramona has a 65% chance temperatures could reach over 100 degrees on Thursday.

With a short heat wave looking increasingly likely for the mid-end of the upcoming week, here are the probabilities of seeing high temperatures over 100 degrees for the Inland Empire and inland. Thursday will likely be the hottest day of the week (PHOTO: National Weather Service)

When in an area under a heat advisory, it is advised to drink plenty of fluids, stay in air conditioning, stay out of the sun and check on relatives and neighbors.

Public cooling centers are available in San Diego County for anyone needing a safe place to stay while heat advisories and warnings are in place.