Los Angeles Weather & Climate Guide: Year-Round Expectations

Travel time: Year-round

Los Angeles is defined by a Mediterranean climate, characterized by warm, dry summers and mild, occasionally rainy winters. However, the sheer size of the metropolitan area and its complex topography—ranging from the Pacific shoreline to over 10,000-foot mountain peaks—create a layered weather experience that defies simple temperature averages.

Typical Weather Patterns and the Diurnal Cycle

The most consistent feature of Los Angeles weather is the Marine Layer. This cool, moist air mass from the Pacific Ocean acts as a natural air conditioner, frequently moving inland at night and the early morning.

  • Morning Transition: It is common to wake up to a thick gray ceiling of low stratus clouds (often called fog or mist by locals).
  • Mid-Day Burn-off: As the sun heats the land, the marine layer retreats toward the coast, usually dissipating by 11:00 AM or noon, replaced by brilliant sunshine.
  • Evening Cool-down: Once the sun sets, the temperature drops quickly. Even on a hot day, the lack of humidity allows heat to escape into the atmosphere, often requiring a light layer after dark.

Seasonal Trends

Spring (March - May)

Spring is often considered the most pleasant season. Rainfall begins to taper off in March, and the landscape turns a brief, vibrant green. Temperatures are mild, but this is also the beginning of the cloudier cycle for coastal residents.

Summer (June - August)

Summer in LA is a tale of two environments. While the rest of the country is sweltering, coastal LA experiences "June Gloom." This phenomenon can stretch into July ("No-Sky July") or August ("Fogust"), where the marine layer is so deep it persists all day at the beaches, keeping them cool and gray while inland valleys are 20°F (11°C) warmer.

Autumn (September - November)

Paradoxically, autumn often brings the year’s highest temperatures. This is the peak season for the Santa Ana Winds—hot, dry winds that blow from the inland deserts toward the sea. These winds drop humidity to single digits and can cause temperatures to spike into the 90s or 100s°F (32–38°C) overnight, also marking the height of the regional fire risk.

Winter (December - February)

Winter is the primary rainy season, though "rainy" is relative. Most precipitation comes from occasional Pacific storms that can bring heavy downpours for two or three days, followed by weeks of crisp, clear, and sunny "Chamber of Commerce" weather. Daytime temperatures frequently hover in the high 60s°F (20°C).

The Microclimate Reality

Los Angeles is a collection of microclimates. On a single July afternoon, you may experience the following variations:

  • The Coast (Santa Monica/Malibu): 72°F (22°C), breezy, and potentially overcast.
  • The Basin (Downtown/Hollywood): 84°F (29°C), sunny, and still.
  • The Valleys (San Fernando/San Gabriel): 98°F (37°C), intense solar heat, and very dry.

Historical Context & Phenomena

The region’s weather is significantly influenced by El Niño and La Niña cycles. El Niño years often bring much heavier winter rainfall and the potential for mudslides in hilly areas, while La Niña years lean toward extreme drought conditions.

Historically, the air quality (smog) was a defining part of the climate. While significantly improved since the 1970s, temperature inversions can still trap pollutants near the surface during heatwaves, creating a visible haze that locals monitor via air quality indices.

What the Weather "Feels Like"

  • Dryness: Outside of the marine layer, the air is semi-arid. High temperatures feel less oppressive than in the humid Eastern US, but the sun's UV intensity is much higher. Sunlight often feels "sharp" or "stinging" on the skin even if the air is cool.
  • The Coastal Chill: Visitors often underestimate the ocean. The California Current is cold; even in mid-summer, the water rarely exceeds 68°F (20°C), and the breeze coming off it can feel biting once the sun drops.
  • Static and Dust: During Santa Ana events, the physical sensation is one of extreme dryness—static electricity is constant, and the air feels charged and restless.