This is taken from surfline.
Here's a basic breakdown of what all the seasons typically experience both surf and wind/weather wise:
Spring: This is a transitional time when both the North Pacific and South Pacific can spit out swell, so we'll often see a peaky combo of NW/WNW and S/SW swells in the water. This is particularly good for the beachbreaks, which really like the cross of swells. We'll often see some of our largest Southern Hemi swells of the year between late March and May to with the Antarctic ice sheet being smallest (less ice equals more open for wind to blow over equals larger fetch/surf). NW windswell really starts to increase too as the North Pacific high settles into a position right off the US West Coast, setting up the aforementioned windswell but also lots of onshore NW wind.
Pros: Good combo of swells, bikinis start showing up on the beach
Cons: Onshore wind, water can get quite cold with the strong NW wind due to upwelling
Summer: South and Southwest Southern Hemi swells pulse in sporadically through the summer months, best in the south facing regions of Orange and Northern LA Counties, as well as select areas in San Diego and Ventura. Unfortunately, long periods of flatness can and often do prevail when storm activity in the South Pacific takes a breather. NW windswell still occasionally kicks up, but is not as strong or consistent as the spring months. S/SE hurricane swells start to make an occasional appearance, generally from August through October.
Pros: warmer water, lots of bikinis on the beach
Cons: long flat spells, crowded lineups, most afternoons are blown out with an onshore wind/seabreeze
Fall: Similar to spring but with generally much better conditions. We can often see a good combo of WNW and S/SW swell, which is again particularly good for the beachbreaks (think about the Fire swell from Oct. 2007). Wind conditions are often excellent as this is the season for Santa Anas and several days with offshore wind all day.
Pros: Good combo of swells, excellent wind conditions, kids are back in school
Cons: Um...maybe slightly less bikinis on the beach?
Winter: Generally larger and more consistent swells out of the W/NW...this is prime season for spots in Santa Barbara, Ventura, South LA and most of San Diego. Weather can deteriorate a bit but often for only a day or two in SoCal before sunny skies and excellent conditions return. Many days with clear blues skies and light wind/glassy conditions all day.
Pros: Generally the largest and most consistent surf of the year, less crowds
Cons: occasional bouts of inclement weather, poor water quality due to run off after rain, colder water and air temps, limited days of bikinis on the beach
Hope that helps!
Honestly it becomes the question of glassiness and crowdiness to me. I guess fall would be the best for me