Southern California is bracing for its first full-week summer surge, with the National Weather Service issuing an extreme heat watch Tuesday through Thursday. Temperatures are forecast to climb from the mid-70s last Saturday to around 90 degrees in downtown Lo
By midweek, the heat is expected to feel like a switch flipped in Southern California.
Between Tuesday and Thursday—described as the first full week of summer—temperatures are forecast to jump sharply across the region. The National Weather Service has issued an extreme heat watch for those days. predicting 90-degree temperatures in downtown Los Angeles and the broader L.A. metro area. That would be a marked rise from a 75-degree high on Saturday, the last day of spring.
The warming won’t be uniform. In the San Gabriel Valley and the San Fernando Valley, highs are expected to reach the mid-90s. In the Antelope Valley and the Cuyama Valley in Santa Barbara County, the forecast could push to 100 degrees or higher. The hottest day is expected to be Wednesday.
The driver, according to Weather Service spokesperson Carol Ciliberti, is “a really strong ridge of high pressure,” centered over Arizona and New Mexico and their southern border with Mexico. That ridge expands westward over Southern California, bringing the sustained heat.
Along with the thermometer jump comes an increased risk of heat-related illness—especially for the young, the elderly, and people without air conditioning. Ciliberti urged residents to stay mindful of pets during the spike: “Do not take your dogs hiking — please.”
Officials also expect the heat wave to briefly lift the familiar “June Gloom” pattern of ocean clouds and fog, even as the marine layer’s grayness may return later. Last March, prolonged high temperatures shattered dozens of records in Southern California.
Next week’s heat is also expected to raise fire risk. In an X post, the Weather Service warned of “drying fuels & tall fire plume potential over the valleys and mountains.”
For many residents, the heat is landing on top of another hazard: smoke and pollution. On Saturday, officials extended a health advisory tied to particle pollution from a massive warehouse fire in Boyle Heights. The advisory remains in effect until 12:30 p.m. Sunday.
Air quality is expected to range from “unhealthy for sensitive groups” to “very unhealthy” across central Los Angeles County, the San Gabriel Valley, the east San Fernando Valley, and the northwest San Bernardino Valley, according to the South Coast AQMD.
Even after daybreak, conditions could shift. The AQMD said air quality may worsen overnight if winds die down. If the wind changes direction Sunday morning, smoke could be pushed toward southeast L.A. County. The AQMD also warned that smoke combined with high humidity could create visibility issues overnight. and that ash could fall in the area.
L.A. County public health officials added a simple precaution if smoke is present: if residents smell smoke, they should avoid vigorous physical activity and stay indoors with doors and windows closed.
The city of Los Angeles, which has declared a state of emergency, opened a smoke respite shelter at Pecan Recreation Center at 145 S. Pecan St. The county opened a similar site in City Terrace Park at 1126 N. Hazard Ave.
All of it is a reminder that the week’s danger isn’t just about feeling hot—it’s about how quickly heat, smoke, and shifting winds can combine to affect people who are most vulnerable.
Southern California heat wave extreme heat watch Los Angeles heat advisory National Weather Service heat illness risk fire risk drying fuels air quality smoke advisory Boyle Heights warehouse fire South Coast AQMD Pecan Recreation Center smoke respite shelter City Terrace Park shelter