Southern California authorities and the National Weather Service warned of sustained extreme heat and issued watches and warnings across large parts of the region as inland temperatures surged past 100 degrees.
The NWS reported a 109 degree reading in Woodland Hills in Los Angeles County and said a broad high pressure ridge over the desert southwest, combined with weakening onshore flow, has trapped heat over the Southland.
Earlier advisories covered parts of San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties, with Orange County under a heat advisory, while an updated extreme heat watch now spans numerous inland valleys and foothill zones from Tuesday through Friday evenings, the weather service said.
The NWS forecast warned overnight temperatures will be five to ten degrees above normal, limiting nighttime relief and elevating the risk of heat-related illness for people without reliable air conditioning.
The watch highlights forecast highs ranging broadly by area, including readings into the low hundreds across the Inland Empire and the possibility of temperatures up to 112 degrees in parts of Los Angeles County, according to the weather service.
Health Risks Fire Danger And Public Guidance
Officials stressed heat illness risk will rise significantly during the event and urged precautions for older adults, children, outdoor workers and anyone without cool shelter, the NWS said.
Public safety guidance from the NWS and local agencies recommends staying hydrated, finding air-conditioned spaces, avoiding direct sun during peak heat, and checking on vulnerable neighbors and relatives.
The Environmental Health and Safety office at UC Irvine advised drinking water frequently, taking breaks in shade or cool areas, avoiding alcohol and excessive caffeine, and resting if symptoms like dizziness or nausea appear.
Federal Occupational Safety and Health Administration recommendations were cited for outdoor workers to take regular rest breaks in shaded or air-conditioned areas and to move anyone showing heat illness symptoms to a cool shaded place immediately.
Officials also warned the prolonged hot, dry conditions increase fire risk across inland terrain and urged caution with ignition sources. For cooling center information, local county pages for Los Angeles, Orange, Riverside and San Bernardino provide locations and hours, the Los Angeles-area notice said.
