Depending on where you live..but I think it is always fun to try something new once and experience it for yourself. I have had fun every time....cannot go wrong tasting wine and enjoying the So. Cal. sun.
not to come off sounding like snob but.....NO. not sure where you are traveling from but if you are in l.a. area...go 2 hr north to pinot country instead
sometimes as early as july to end of august is harvest for most temecula (california) wineries. Right now i bet you could go and you'll see little buds of grape going.
i went to napa in March and it was sad seeing all the barren grape vines =)