El Centro is another favorite place, though there is aerial spraying and some natural desert dust. Up the road there are lots of parks near Palm Springs. The biggest congregation of snowbirds is in the Hemet area. It is not typical of Southern California. It's more rural.
Monthly rates are more.
All the good parks will fill up early. So if you're planning on going somewhere for sure for January and February, be sure and have your reservations early. If you're new to snowbirding, pick your first park where you have a friend. That will help get you up and running. Before you settle in on one special park, try out as many different places as you can, first.