Sun bathing

I guess it depends where you are sun bathing, in you back yard and in complete privacy I don't think you would even need a bathing suit! At a public beach or pool at most spots in the us a bathing suit is proper, but then again there are nudists beaches and camps around too.

Yes. It is called the "Indecent Exposure" law. As long as you are in or around a public place, or can be viewed from a public place, you can be charged for breaking this law. Most officers though will usually just ask you to please cover yourself unless you are a repeat offender.

There are laws against nude sunbathing, but there are some areas and some beaches that are sanctioned for it. such as playalinda beach in Florida http://goflorida.about.com/cs/floridabeaches/p/bch_playalinda.htm

Check your local laws and find out where you can sun bathe nude legally.

Sun bathing is legal on all beaches as long as your private parts are covered. So proper swim wear and bathing suits should be worn.

I think it should be legal to nude sunbath even in the winter time, any where, as long as you dont show in public, and that should be the law, that you can ,