It's a little too early for leaves to fall off here in Los Angeles. It just dropped into the low 50s at night for the first time in months, it will be late November, early December before we get any moderately cold weather. The hottest months here are often September and October instead of July and August like the east coast. It also depends on the trees, you don't have the same kind of variety here as you have back east, you don't get much of a color change either. We often get wind this time of year as well and that takes care of the types of trees that lose their leaves.
There really isn't a "fall" or "spring" here and I only wore my heavy coat about 3 days last "winter".
Looking historically at weather in January in Los Angeles the average high temperature for the month is 68 and the average low is 48.