Nights can be cool any time of the year.
In the summer, the coastal side of the mountains is generally 10 to 15 degrees cooler than the inland side. In the winter this pattern is reversed with warmer temperatures along the coast. Layer your clothing to be comfortable anywhere in the mountains. For safety and comfort, use a hat, sunscreen and appropriate shoes or boots. The Santa Monica Mountains National Recreation Area is located west of Griffith Park in Los Angeles County and to the east of the Oxnard Plain in Ventura County.