I'm not sure which months are prone to sundowner winds. I think it's in the winter mostly on warm days. They come usually right at sunset and are pretty rare in SB really. But when they come they blow straight offshore and are very warm and very gusty. I don't know if there is a distinct difference between sundowner winds and Santa Ana winds. You can tell when a mild Santa Ana is in effect because the smog from LA will blow out to sea and you'll see a narrow yellow band of smog out by the islands.