Wednesday, July 15, 2026

Extreme Heat Warning for Pasadena, San Gabriel Valley Remains in Effect Through Thursday

An extreme heat warning covering Pasadena, Altadena and the rest of the San Gabriel Valley remains in effect through 8 p.m. Thursday, with the National Weather Service forecasting Wednesday as the hottest day of the stretch.

The warning, which took effect at 10 a.m. Tuesday puts much of inland Los Angeles County under a high risk of heat-related illness as temperatures climb toward the triple digits, with a Pasadena high forecast near 98 degrees before an increase in onshore flow begins to ease conditions Thursday. County and city officials have pointed residents to cooling options and urged extra care for older adults, young children and people without air conditioning.

The Weather Service said temperatures across the valleys, lower mountains and far interior would range from the 90s to as high as 110 degrees, with the interior hottest. “Wednesday will be the warmest day,” the agency said, forecasting an additional 3 to 6 degrees of warming. In the San Fernando Valley, highs were forecast to reach 110 on Wednesday and about 104 on Thursday, with roughly 10 degrees of cooling expected Friday.

Lingering monsoonal moisture will raise humidity and could bring a 20% to 40% chance of showers or thunderstorms in the mountains and Antelope Valley, forecasters said. Overnight lows Wednesday night were expected to stay in the lower 70s in many communities, offering little relief and adding to the illness risk.

In a statement, the Los Angeles County Office of Emergency Management said cooling centers were open across the county, many at libraries, parks and other community spaces. “Extreme heat can create serious challenges for many residents, and no one should feel they have to endure these conditions alone,” Board Chair and First District Supervisor Hilda L. Solis said in the county statement. The county’s emergency management director, Kevin McGowan, said the county plans for extended heat on an ongoing basis and asked residents to “team up with us in protecting themselves and each other.” Residents can find a cooling center at ready.lacounty.gov/heat or by calling 211.

The City of Pasadena, which operates its own public health department, said its departments were coordinating to keep residents cool and informed. The city pointed residents to air-conditioned relief at public libraries — not designated cooling centers but open during regular hours — and to pools and splash pads including the John J. Kennedy Pool on North Fair Oaks Avenue, the La Pintoresca Park splash pad and the Rose Bowl Aquatics Center. Pasadena Water and Power urged customers to set thermostats to 78 degrees or higher and to limit use of large appliances during peak hours of 4 to 9 p.m. Pasadena Dial-A-Ride offers rides to cooling locations at (626) 791-7200.

In its statement, the county urged residents to stay indoors from 10 a.m. to 3 p.m., cover windows with drapes, shades or blinds, and set air conditioning between 75 and 80 degrees; those without air conditioning were encouraged to take a cool shower twice a day and visit a public air-conditioned facility. It advised drinking two to four glasses of water an hour, avoiding alcohol and, during exercise or outdoor work, replacing lost salt and minerals with low-sugar fruit juices or sports drinks. Residents were told to wear a wide-brimmed hat and light-colored, lightweight, loose-fitting clothing outdoors and to use sunscreen of at least SPF 15 if they will be in the sun.

The county also warned against leaving anyone, especially a child, unattended in a pool, and against leaving children or pets in parked cars, and it reminded residents to keep pets indoors or shaded with water, noting hot pavement can burn their paws. Dr. Muntu Davis, the county health officer, has said heat causes more deaths in the U.S. each year than floods, storms and lightning combined. Residents can sign up for alerts at alert.lacounty.gov, and officials said to call 911 for signs of heat stroke, including a body temperature of 103 degrees or higher, confusion, dizziness or nausea.