If you haven’t lived in coastal California (west of the inland valleys, west of the major mountain ranges), it’s hard to describe how comfortable it is. Perhaps a bit of data will help –
City-data.com (http://www.city-data.com) has a wonderful collection of metrics on US cities and towns. Let’s look at Menlo Park, a town in the San Francisco Bay area, near the town where I live.
Average Climate in Menlo Park, California – based on data reported by over 4,000 weather stations
What does this tell us? Spring, summer and fall have warm (not hot!) days and cool nights. In winter the weather is mild (doesn’t freeze) and it rains a bit. It doesn’t rain in spring, summer or most of fall. There are a sunny days, even in winter.
It’s also not humid, so it’s really, really comfortable.
I’ve tried to think of a few disadvantages to the weather. When you live in the land of perfect comfort it’s hard to come up with anything. Let’s see – you have to remember to bring a jacket in summer – after the sun sets it gets chilly. And night swimming isn’t great around here – it’s hard to force yourself to get into a pool when you are wearing a jacket over your swimsuit.