Kicking off with weather in LA in December, this is a crucial time for outdoor enthusiasts and travelers alike. The winter season brings a mix of cool temperatures, mild sunshine, and unpredictable rainfall.
Los Angeles is known for its mild winter climate, but December can be quite chilly, with average highs in the mid-60s and lows in the mid-40s. The Pacific Ocean’s influence keeps temperatures relatively mild, but cold fronts can still bring rain and wind.
Understanding La Niña’s Impact on Weather in Los Angeles in December: Weather In La In December
La Niña, the ocean-atmospheric phenomenon, plays a significant role in shaping the winter weather patterns in Los Angeles. In December, La Niña’s influence on temperature fluctuations, winter precipitation, and snowfall is particularly noteworthy. Let’s dive deeper into the world of La Niña and its effects on LA’s winter weather.
Understanding La Niña’s effects on temperature fluctuations in December requires an examination of the phenomenon’s impact on atmospheric circulation patterns. During a La Niña event, the Pacific Ocean’s surface temperature cools down, leading to increased atmospheric pressure near the equator and decreased pressure near the poles. This pressure gradient causes winds to blow from high to low pressure, resulting in a more southerly flow of air in the western United States, including Los Angeles. As a result, temperatures in LA tend to be milder than average in December, with average high temperatures ranging from 64°F to 65°F (18°C to 18.3°C). However, it’s worth noting that La Niña’s effects on temperature can be highly variable from year to year.
Previous La Niña Events in LA’s Winters
In the past, La Niña events have significantly impacted LA’s winter weather. For example, during the 2011-2012 La Niña event, Los Angeles experienced below-average temperatures, with the average temperature being 55.6°F (13.1°C). This La Niña winter resulted in heavy rainfall, with total precipitation reaching 7.51 inches (191.2 mm) in the Downtown LA area. Another notable event was the 2016-2017 La Niña, which led to record-breaking rainfall in the Western United States. This event resulted in widespread flooding in California, including LA County.
Pacific Decadal Oscillation (PDO) and Winter Precipitation Patterns
The Pacific Decadal Oscillation (PDO) is a climate pattern that affects the Pacific Ocean’s surface temperature and atmospheric pressure. The PDO’s phase can significantly impact the winter precipitation patterns in Los Angeles. During a positive PDO phase, the Pacific Ocean’s surface temperature warms up, leading to increased atmospheric pressure near the equator and decreased pressure near the poles. This pressure gradient causes winds to blow from high to low pressure, resulting in a more northerly flow of air in the western United States, including Los Angeles. As a result, LA tends to receive more rainfall during positive PDO phases. In contrast, negative PDO phases tend to result in drier winters due to the southerly flow of air.
El Niño Southern Oscillation (ENSO) and Snowfall in LA
The El Niño Southern Oscillation (ENSO) is a climate pattern that affects the Pacific Ocean’s surface temperature and atmospheric pressure. The ENSO’s phase can significantly impact the snowfall in Los Angeles. During El Niño events, the Pacific Ocean’s surface temperature warms up, leading to increased atmospheric pressure near the equator and decreased pressure near the poles. This pressure gradient causes winds to blow from high to low pressure, resulting in a more northerly flow of air in the western United States, including Los Angeles. As a result, LA tends to receive more rainfall and snowfall during El Niño events. During La Niña events, the Pacific Ocean’s surface temperature cools down, leading to decreased atmospheric pressure near the equator and increased pressure near the poles. This pressure gradient causes winds to blow from high to low pressure, resulting in a more southerly flow of air in the western United States, including Los Angeles. As a result, LA tends to receive less rainfall and snowfall during La Niña events.
Data Illustrating La Niña’s Impact on LA’s Snowfall
According to data from the National Centers for Environmental Prediction (NCEP) and the National Oceanic and Atmospheric Administration (NOAA), during the past 10 La Niña events (1995-1996 to 2017-2018), Los Angeles received below-average snowfall in 9 out of 10 events. The data also show that the mean snowfall in LA during La Niña events is significantly lower than the average snowfall during neutral ENSO phases.
Typical Winter Weather Patterns in Los Angeles in December
Los Angeles in December, a perfect blend of cool and sunny days, making it an ideal time to explore the city. The winter season in LA is characterized by mild temperatures, low humidity, and ample sunshine, making it a popular destination for tourists and locals alike.
Average Temperature in December
The average temperature in LA during December ranges from 48°F (9°C) to 63°F (17°C), making it an ideal time to enjoy outdoor activities such as hiking, surfing, and biking. The temperature is usually at its lowest in early December, with an average low of 45°F (7°C) and a high of 58°F (14°C). As the month progresses, the temperatures gradually rise, with an average high of 61°F (16°C) and a low of 50°F (10°C) by the end of December.
Precipitation in December
December is one of the driest months in LA, with an average of 2.76 inches (70 mm) of precipitation. The city typically experiences an average of 6-7 days with measurable precipitation, with most of it coming in the form of light drizzles and gentle showers. While precipitation is relatively low, LA can experience occasional heavy downpours, so it’s essential to stay prepared.
Sunshine Hours in December
Los Angeles enjoys an average of 283 sunshine hours in December, with an impressive 75% of possible sunshine. This makes it an ideal time to enjoy the great outdoors, explore the city’s many parks and beaches, and soak up some Vitamin D.
Comparison with other Major US Cities in December
LA’s winter weather is unique compared to other major US cities in December. Cities like New York and Boston experience colder temperatures and more precipitation, while cities like Miami and San Diego enjoy warmer temperatures but more humidity. LA’s mild climate, along with its ample sunshine, makes it an attractive destination for people looking to escape the harsh winter weather elsewhere.
Clouds in December
The skies in LA during December are usually dominated by high-level clouds, such as cirrus and altocumulus, which are often thin and wispy. These clouds tend to form at high altitudes, making them less dense and more likely to dissipate quickly. This results in plenty of sunshine and clear blue skies, perfect for stargazing and outdoor activities.
Best Activities to Enjoy in December
December is a great time to explore LA’s many attractions and enjoy outdoor activities. Some popular things to do in LA during December include:
- Hiking: With mild temperatures and plenty of sunshine, December is an ideal time to explore LA’s many hiking trails.
- Surfing: With temperatures ranging from 48°F to 63°F, December is a great time to catch some waves in LA’s many beaches.
- Biking: LA’s bike lanes and trails are perfect for a leisurely ride, and the cool temperatures make it an ideal time to explore the city.
- Stargazing: With clear blue skies and minimal light pollution, LA is a great destination for stargazing and astronomy enthusiasts.
Unpredictable Rainfall in LA during December
Los Angeles is known for its unpredictable weather patterns, and December is no exception. The region’s unique geography, combined with the presence of different low-pressure systems, makes rainfall a challenging forecast to predict. However, understanding the various factors at play can provide valuable insights into the complex weather dynamics of LA during December.
Different Types of Low-Pressure Systems
Several low-pressure systems affect LA during December, each with its unique characteristics. These systems include:
The subtropical jet stream, which brings warm, moist air from the Gulf of California.
The North Pacific High, a large high-pressure system that dominates the region’s weather patterns.
The Aleutian Low, a subpolar low-pressure system that influences weather in the western United States.
The polar jet stream, which can bring cold, dry air from the Arctic.
These low-pressure systems interact and influence each other, leading to complex and often unpredictable weather patterns. The trajectory of rain-bearing storms is further impacted by wind patterns.
Wind Patterns and Rain-Bearing Storms
Wind patterns play a significant role in determining the trajectory of rain-bearing storms in December. The jet stream, in particular, can steer storms into or out of the region, leading to varying levels of rainfall. The position and intensity of the wind patterns can also impact the type of precipitation that hits LA, with some storms producing heavy downpours and others bringing light, scattered showers.
The Sierra Nevada Mountain Range
The Sierra Nevada mountain range acts as a barrier, directing moisture-laden air towards LA. When low-pressure systems pass over the mountains, they force the air to rise, cool, and condense, resulting in precipitation. The amount of rainfall that reaches LA depends on the strength of the low-pressure system and the position of the mountain range.
Neighborhood Rainfall Averages
Here’s a table showing the average rainfall in different neighborhoods of LA during December:
| Neighborhood | Average Rainfall (Dec) |
|---|---|
| Fairfax District | 1.3 inches |
| Rancho Park | 1.5 inches |
| Miracle Mile | 1.2 inches |
| Playa del Rey | 2.1 inches |
As this table shows, rainfall can vary significantly across different neighborhoods in LA during December, highlighting the importance of accurate forecasting and weather analysis.
Impact of Weather on LA’s Outdoor Activities in December
In December, Los Angeles’ weather can be quite unpredictable, affecting various outdoor activities. From beaches to hiking trails, theme parks, and more, the city’s weather can either make or break your outdoor plans. In this section, we’ll explore how dry or wet weather conditions impact LA’s popular outdoor spots and provide you with the best strategies for managing crowds on rainy days.
Beach Activities
While LA’s beaches are a major attraction, wet weather can dampen your beach plans. However, some beaches are less affected by rain than others. For instance, beaches with strong waves and currents, such as Malibu Beach and Manhattan Beach, can be a hit even on rainy days. On the other hand, beaches with calm waters, like Santa Monica Beach and Venice Beach, may be less appealing when it’s raining.
Hiking Trails
Hiking trails in LA are a favorite among locals and tourists alike. However, wet weather can make trails muddy and slippery, making them hazardous to navigate. The trails at Runyon Canyon Park and Griffith Park are popular but may be more challenging during rainy days. It’s essential to check trail conditions before heading out and consider alternative trails that are less affected by rain.
Theme Parks
Theme parks like Universal Studios Hollywood and Disneyland are always a hit during the winter months. However, wet weather can make certain attractions and rides more challenging or even closed. It’s best to check the park’s weather policy and plan your visit accordingly. Additionally, consider visiting during off-peak hours or on weekdays when the crowds are smaller.
Crowd Management Strategies
If you do decide to visit outdoor attractions on a rainy day, here are some strategies for managing crowds:
– Arrive early or visit during off-peak hours to minimize wait times.
– Consider visiting indoor attractions, such as museums or indoor shopping centers.
– Use online resources, like crowd calendars or weather apps, to plan your visit.
– Be prepared for security checks and longer lines.
Costs of Outdoor Activities
Participating in outdoor activities during a dry winter can be significantly cheaper than doing so on a wet winter day. For instance, hiking trail entrance fees and beach parking fees may be lower when it’s not raining. Additionally, you may be able to find better deals on outdoor gear and equipment during the off-season.
“Indoor activities are not just a backup plan, but a great way to experience LA’s culture and entertainment scene. From museums to indoor skydiving, there’s something for everyone in LA that’s dry and fun!”
Unique Factors Contributing to LA’s Weather in December
Los Angeles in December is a unique blend of Mediterranean and subtropical climates, influenced by various local and global factors. One of the key aspects that set LA apart from other cities in the world is its diverse geography, featuring mountains, valleys, and coastlines. This diversity creates a complex weather pattern that is influenced by several unique factors.
The Urban Heat Island Effect: Impact on Nighttime Temperatures
During the night, LA’s urban heat island effect comes into play, significantly warming up the city’s temperatures due to the concentration of buildings, roads, and other heat-absorbing features. Research has shown that nighttime temperatures in urban areas can rise by up to 10°F (5.6°C) compared to surrounding rural areas. This phenomenon is particularly pronounced in LA, where the heat island effect is amplified by the city’s sprawling metropolis.
Local Factors Influencing Fog Formation in LA
Fog is a common occurrence in LA during the winter months, particularly in December. The formation of fog is largely influenced by local factors, including temperature inversions, air humidity, and wind direction. Temperature inversions occur when a layer of warm air forms over a layer of cold air, trapping moisture and creating a foggy atmosphere. LA’s coastal location and proximity to the Santa Monica Bay also contribute to fog formation, as moist air from the ocean is cooled and condenses, creating a thick fog.
Impact of Nearby Bodies of Water on LA’s Climate, Weather in la in december
The Pacific Ocean and Santa Monica Bay play a crucial role in shaping LA’s climate. The ocean’s moderating influence helps regulate LA’s temperatures, keeping them relatively mild compared to inland areas. The bay, in particular, has a significant impact on LA’s coastal weather patterns, creating a microclimate that is distinctly different from the rest of the city. Additionally, the ocean’s proximity helps regulate LA’s humidity levels, making the city’s climate relatively dry compared to other parts of the world.
Extreme Weather Events in LA During December
LA is no stranger to extreme weather events, particularly in December. Some notable examples include:
- January 2007: A powerful storm system brought heavy rainfall and strong winds to LA, causing widespread power outages and flooding.
- December 2010: A cold front brought freezing temperatures and significant snowfall to the Los Angeles area, making it the first measurable snowfall in the city since 1949.
- January 2018: A prolonged heatwave struck LA, breaking temperature records and causing widespread power outages.
These extreme weather events highlight the complexity and unpredictability of LA’s climate, making it essential to stay informed and prepared for any weather-related challenges that may arise.
Conclusion
In conclusion, understanding the weather patterns and activities in LA during December is essential for making the most of your winter trip. From enjoying the mild sunshine to navigating the rain and wind, we hope this guide has provided you with valuable insights and tips for planning your next adventure in LA.
Query Resolution
What is the average temperature in LA in December?
The average high temperature in LA in December is around 66°F (19°C), while the average low temperature is around 45°F (7°C).
Can I expect rain in LA in December?
Yes, LA receives an average of 2.5 inches (64 mm) of rainfall in December, with an average of 7 rainy days throughout the month.
Are there any outdoor activities I can enjoy in LA in December?
Yes, LA offers plenty of outdoor activities during the winter season, including hiking, surfing, and visiting local beaches and parks.
