When will you be there it is typical Southern California weather.One of the best times to go is in May - June the weather is clear days.Nov - Feb isn usually the rainy season.
If you're talking about the Disnetland in California, then I would say that the weather is typically fairly warm, in the 60's or 70's and clear skies. A nice place to visit and spend the day outside.
It does not rain often and is usually sunny. September, May and November provide the best weather. August is the worst for hot weather, January the worst for cold weather.
A lot of this is going to depend on the time of year that you visit, but being in California means that the weather is going to be warm and not too hot in the Summer.