Los Angeles, California — Southern California is experiencing another stretch of above-average December warmth, with temperatures soaring well beyond typical seasonal norms across coastal and inland communities. Forecasters say the region will hold onto the warmer pattern for several days before a modest cooldown arrives heading into the weekend.
High Pressure System Delivers Elevated Temperatures Across the Region
According to meteorologists, a persistent ridge of high pressure is the primary driver behind the unusual conditions. The system has settled over the West Coast, limiting cloud formation and enhancing warming across the basin. Forecast models show that the ridge will remain largely stationary through midweek, maintaining temperatures far above the seasonal averages.
By midday Tuesday, widespread readings in the upper 70s and low 80s were already recorded across the region. Los Angeles hit 80 degrees, with Van Nuys reaching 78, Santa Ana climbing to 77, and Riverside registering 79 degrees under clear skies. Farther east in the Coachella Valley, Palm Springs topped out at 81 degrees, offering another day of near-summer conditions despite the calendar.
Meteorologists note that these values represent temperatures 10 to 20 degrees above normal for early December. Coastal communities, which typically experience the most stable temperatures this time of year, also saw unusually warm readings as the ridge pushed marine influence farther offshore.
Air quality monitors reported “good to moderate” conditions for most of Southern California, allowing residents to take advantage of the dry, sunny weather without elevated pollution concerns.
Santa Ana Winds Intensify Warmth and Raise Fire Weather Concerns
Compounding the temperature rise, another round of Santa Ana winds has swept across portions of Southern California. These dry, downslope winds — characteristic of fall and winter — funnel through canyons and passes, accelerating rapidly and bringing warmer, drier air to the surface.
Forecasters report gusts reaching 30 to 35 mph in parts of the Santa Clarita Valley and eastern Ventura County. Some isolated areas could see gusts approach 40 mph before tapering off late Wednesday into Thursday.
While the winds enhance daytime heating, they also increase fire weather sensitivity across local foothills and inland communities. Even though no major red-flag warnings are active at this time, officials urge residents to remain mindful of the dry conditions and to avoid activities that could spark accidental fires.
Meteorologists expect a gradual weakening of the Santa Ana winds by Thursday, though light offshore flow may linger.
Temperature Pattern to Shift Slightly as Low-Pressure System Approaches
By late Thursday into Friday, forecast models show a weak low-pressure system shifting closer to the West Coast, helping to disrupt the stagnant ridge overhead. This transition is expected to introduce slightly cooler air and increased marine-layer clouds along the coast.
Despite the change in pattern, the cooldown will be measured rather than dramatic. Daytime highs through the upcoming weekend are expected to settle into the low to mid-70s for many Southern California cities — still above average, though noticeably cooler than the peak warmth seen earlier in the week.
Forecasters anticipate inland valleys will experience the biggest drop, though temperatures will remain comfortable for outdoor activities. By early next week, warming is expected to resume as the ridge rebuilds, bringing temperatures back into the upper 70s.
Looking Ahead
As winter continues, meteorologists caution that Southern California may experience more rapid temperature fluctuations, especially when alternating between Santa Ana events and incoming low-pressure systems. Nonetheless, the region is currently set for a mild stretch of weather, with no major rain systems expected in the immediate forecast.
Share Your Thoughts
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