December in Los Angeles presents a fascinating study in contrasts, where the Pacific Ocean’s cooling influence meets the lingering warmth of the high desert. While much of the Northern Hemisphere braces for freezing temperatures, the City of Angels offers a more temperate escape, blending mild days with crisp, clear evenings. Understanding the specific temperature patterns, daily highs and lows, and microclimates unique to this month is essential for both residents planning their routines and visitors crafting the perfect holiday itinerary.
Typical December Temperature Range
Los Angeles experiences its mildest weather of the year in December, a direct result of low summer humidity and the stabilizing effect of the Pacific. The average daily high typically sits between 68°F (20°C) and 72°F (22°C), providing a comfortable baseline for outdoor activities without the intense summer heat. Nighttime temperatures, however, tell a different story, with average lows often dipping to between 48°F (9°C) and 52°F (11°C). This significant drop after sunset creates the classic Southern California evening, perfect for layering a light jacket over a long-sleeved shirt.
Regional Variations Across the Metro Area
The sprawling geography of Los Angeles means that "the temperature" is never a single number, a fact that becomes starkly apparent in December. The coastal areas, including Santa Monica, Venice, and Marina del Rey, benefit from consistent ocean breezes that keep conditions cooler and more humid, with highs rarely exceeding 70°F. Just a few miles inland, in neighborhoods like Downtown LA, Koreatown, or Pasadena, the urban heat island effect and increased distance from the water can raise afternoon temperatures by several degrees. The valleys, such as the San Fernando and San Gabriel, experience the most dramatic shifts, with daytime warmth often giving way to chilly nights that can occasionally flirt with the freezing mark, especially in the foothills.
What to Pack for a December Visit
Packing for Los Angeles in December is an exercise in strategic layering, as you will likely encounter sun, wind, and cool temperatures all in a single day. Lightweight sweaters, long-sleeve tops, and comfortable pants are the foundation of your wardrobe, providing warmth without the bulk of heavy winter clothing. A medium-weight jacket or a stylish leather bomber is non-negotiable for evenings, particularly if you plan to be near the coast or in shaded areas. Footwear should prioritize comfort for walking, with waterproof shoes being a wise choice for the occasional morning drizzle. Don’t forget sunglasses for the bright afternoons and a scarf for those unexpectedly chilly valley mornings.
Rainfall and Its Impact on Temperature
While December is technically the beginning of Los Angeles’s wet season, significant rainfall is not a daily occurrence. The month typically sees an average of 2 to 3 inches of precipitation, often falling in a few concentrated storms. These rain events, however, have a direct and immediate cooling effect, temporarily suppressing the daytime high by 5 to 10 degrees. When the skies clear, the absence of cloud cover allows for rapid evening cooling, leading to the sharpest temperature swings of the season. This dynamic makes checking the daily forecast crucial for planning outdoor excursions, as a rainy morning can quickly transition into a pleasant, clear afternoon.
December Daylight and Sunset Times
The winter solstice on December 21st or 22nd marks the shortest day of the year, a fact that subtly influences the perceived temperature. In early December, Los Angeles enjoys approximately 10 hours of daylight, with sunrise around 6:45 AM and sunset near 4:45 PM. By month’s end, the days have extended by nearly an hour, with sunrise closer to 7:00 AM and sunset after 5:00 PM. This limited daylight means that the ambient warmth of the sun is available for a shorter period, contributing to the cooler feel of the mornings and late afternoons. Planning sightseeing for the middle of the day ensures you maximize the warmest and most comfortable hours.
