Los Angeles Weather In December Your Guide: What to Expect, How to Prepare, and Where to Go

December in Los Angeles marks the formal onset of winter, bringing the city’s first meaningful rainfall and a noticeable dip in temperature. This guide details typical conditions, from average temperatures and rainfall to practical advice for residents and visitors. Understanding these patterns helps ensure comfort and safety while navigating the city during the holiday season.

While Southern California remains mild compared to much of the nation, December serves as a critical transition period. It is a time when residents trade light summer attire for layers, and tourists balance sunscreen against the occasional chill. The month is defined by a shift from dry heat to a wetter, cloudier climate, setting the stage for the region’s distinct seasonal rhythm.

Typical December Conditions

December is statistically the coldest month in Los Angeles, though "cold" is a relative term in this Mediterranean climate. The influence of the Pacific Ocean keeps temperatures moderate, preventing the extreme cold seen in inland and eastern regions.

Temperature Averages

The monthly climate is characterized by the following averages, providing a reliable baseline for planning:

• Average High: Approximately 68°F (20°C). This represents the daytime peak, often occurring in the mid to late afternoon.
• Average Low: Around 48°F (9°C). Overnight and early morning temperatures can feel quite cool, necessitating warmer clothing.
• Record Extremes: Historical records show a range from a low of 28°F (-2°C) in 1962 to a high of 88°F (31°C) in 1963. Such extremes are rare but illustrate the variability within the season.

"December really is the start of the true winter season here," notes Greg Wayne, a meteorologist with the National Weather Service in Los Angeles. "You see a distinct drop in average temperatures, and for the first time all year, we routinely see overnight freezes in the valleys and at higher elevations, even if the coast stays relatively mild."

Rainfall and Humidity

December is the beginning of Los Angeles’s wet season, which typically runs from November through March. The month averages about 3 to 4 inches of precipitation, a significant increase from the bone-dry summer months.

• Precipitation Days: Rain occurs on roughly 4 to 5 days during the month.
• Storm Systems: Most rainfall is associated with Pacific storm systems, which can deliver short, intense downpours or longer, steadier periods of rain.
• Humidity: Average humidity levels rise, often feeling damp during and after rain events. Coastal areas tend to be foggier and more humid than inland valleys.

Regional Variations Across the Region

Los Angeles is not a monolithic city; its weather in December varies dramatically based on geography. This "microclimate" effect is one of the defining features of Southern California weather.

The Coastal Corridor

Areas along the Pacific Ocean, such as Santa Monica, Venice, and Marina del Rey, experience the moderating influence of the sea. These locations enjoy milder temperatures year-round.

• Temperature: Highs are typically a few degrees cooler than inland, while lows are significantly warmer, rarely dipping below freezing.
• Marine Layer: Morning fog and low clouds are common, often burning off by midday. This creates a cooler, more overcast atmosphere compared to the sunny valleys.

Inland Valleys and Downtown

Communities in the San Fernando and San Gabriel Valleys, as well as downtown Los Angeles, experience more temperature extremes. These areas heat up quickly during the day and cool down rapidly at night.

• Temperature Swings: It is not uncommon for the temperature in the San Fernando Valley to be 10-15 degrees warmer than at the beach in the afternoon, only to be several degrees colder after sunset.
• Rainfall: These areas receive slightly less rainfall than the coast but are more prone to temperature fluctuations.

Mountain and Higher Elevation Zones

For residents and visitors in the Angeles National Forest, San Gabriel Mountains, or areas like Santa Clarita and Lancaster, winter is a distinct season.

• Snow: Higher elevations, such as Mount Baldy (Baldy Bowl) and areas near Wrightwood, regularly receive snowfall. December is often the first month these areas see significant accumulation.
• Freezing Temperatures: Freezing temperatures are the norm, and ice storms can occur, impacting road conditions and daily life.

Practical Preparation and Lifestyle Adjustments

The shift in weather necessitates changes in how residents dress and conduct their daily activities. Preparation is key to navigating the month comfortably.

Wardrobe Essentials

Gone are the days of shorts and tank tops. The December wardrobe is built on layers:

1. Base Layers: Lightweight thermal tops and leggings provide warmth without bulk.
2. Mid Layers: Fleece jackets, wool sweaters, and flannel shirts offer insulation.
3. Outer Layers: A waterproof or water-resistant jacket is essential. While not every storm is a deluge, windbreakers and raincoats are indispensable.
4. Accessories: Scarves, beanies, and gloves are common sights, especially in the mornings and evenings.

Home and Vehicle Preparedness

While snow is not a concern in most populated areas, the rain introduces specific challenges.

• Rain Gear: Keep an umbrella in your car and at your desk. Waterproof boots are a valuable asset.
• Vehicle Checks: Ensure your windshield wipers are in good condition and your tires have adequate tread. Rain can turn streets slick, especially after the first dry spell.
• Home Maintenance: Clear gutters of leaves to ensure proper drainage. Check for any leaks in roofs or windows before the first major storm arrives.

Where to Go and What to Do

December weather opens up a unique set of activities, blending classic Southern California outdoor fun with seasonal, indoor festivities.

Embracing the Outdoors

The mild temperatures make it ideal for hiking and sightseeing, provided you are prepared for potential rain and cooler mornings.

• Hiking: Trails in Griffith Park, Runyon Canyon, and the Santa Monica Mountains are accessible. However, conditions can be muddy and slippery after rain, so sturdy footwear is a must.
• Beaches: While swimming is uncommon, beaches like Santa Monica and Venice are far less crowded. It is a perfect time for long walks, beachcombing, and watching surfers in the colder, choppy water.

Seasonal and Cultural Events

The holiday season is in full swing, and the weather complements the festive atmosphere.

• Light Displays: Events like the Magic Boat Parade in Pasadena and various neighborhood light shows are best viewed in the cool, clear(ish) evening air.
• Indoor Activities: Rainy days are perfect for visiting world-class museums such as The Getty Center, the Grammy Museum, or catching a performance at the Dolby Theatre. Rainy days in LA are often the best days for cultural exploration.