Southern California is bracing for a significant heat wave expected to peak between Tuesday and Thursday this week, marking the first full week of summer. The National Weather Service has issued an extreme heat watch for the region, with temperatures forecasted to rise sharply from the mid-70s last Saturday to the 90s and potentially higher in several areas.

Downtown Los Angeles and the surrounding metropolitan area are expected to reach highs near 90 degrees, while the San Gabriel Valley and the San Fernando Valley could see temperatures climbing into the mid-90s. Some inland locations, including the Antelope Valley and the Cuyama Valley in Santa Barbara County, may experience temperatures reaching or exceeding 100 degrees. Wednesday is anticipated to be the hottest day of the stretch, according to National Weather Service spokesperson Carol Ciliberti.

The heat surge is attributed to a potent ridge of high pressure centered over Arizona and New Mexico that extends westward, enveloping Southern California. This atmospheric pattern suppresses typical coastal marine layers, often associated with "June gloom," offering a temporary break from the region’s usual early summer cloud cover.

Officials have expressed concern over increased risks tied to the heat wave, particularly heat-related illnesses affecting vulnerable populations such as children, the elderly, and those lacking adequate cooling. Public health advisories emphasize avoiding outdoor exertion and caution against taking pets hiking during this period.

Additionally, the extreme heat heightens the danger of wildfires, with drying vegetation and elevated fire plume potential across valleys and mountainous terrain noted by the weather service. This comes amid ongoing air quality concerns following a massive warehouse fire in Boyle Heights that prompted a health advisory extending into Sunday afternoon.

The South Coast Air Quality Management District (AQMD) has forecasted air quality to range from "unhealthy for sensitive groups" to "very unhealthy" across central Los Angeles County, the San Gabriel Valley, the eastern San Fernando Valley, and the northwestern San Bernardino Valley. The combined presence of smoke and high humidity is expected to reduce visibility, and ash fall remains a possibility.

Public health officials recommend that residents exposed to smoke avoid strenuous physical activity and remain indoors with windows and doors closed. In response to the deteriorating air quality, the city of Los Angeles, which has declared a state of emergency, opened a smoke respite shelter at Pecan Recreation Center, 145 S. Pecan St. The county also established a shelter at City Terrace Park located at 1126 N. Hazard Ave.

As the heat wave progresses, officials urge residents to stay informed of changing conditions and take necessary precautions to protect health and safety.