The NWS San Diego office issued a Heat Advisory on Monday, covering the San Bernardino and Riverside County Valleys–The Inland Empire, the San Diego County Inland Valleys, and the Orange County inland areas.
Inland valleys across Orange, Riverside, San Bernardino, and San Diego counties are forecast to reach up to 34°C (94°F) on Tuesday, October 28, and 36°C (97°F) on Wednesday, October 29.
The advisory will remain active from 11:00 local time (LT) on Tuesday through 19:00 LT on Wednesday.
Meanwhile, the NWS Los Angeles/Oxnard office has extended its existing advisory for Los Angeles and Ventura counties, covering inland coastal areas, the San Fernando and San Gabriel valleys, and the Santa Monica Mountains.
Maximum temperatures near 34°C (93°F) are forecast, with the advisory in effect from 10:00 LT on Tuesday through 19:00 LT on Wednesday.
References:
1 Heat Advisory – NWS – October 27, 2025