Florida has a tropical climate, which means that you can enjoy going to the beach at any time. However, winter does bring chilly temperatures to the state especially in its northern and central parts. Jacksonville and Daytona Beach can get rather cold in the winter. Tampa, Miami and the Florida Keys enjoy warmer winters but still don't expect the Caribbean kind of weather. If you plan to indulge in sunbathing and swimming, it's better to avoid the colder months between December and March.
When talking about beach destinations in Florida, there is clearly one winner. Key West is the southernmost and the loveliest beach spot—a true paradise on Earth. Fort Zachary Taylor State Park is one of Florida's most beautiful spots, with wide stretches of soft sand and calm waters. Key Siesta is another great spot for beach lovers.
Clearwater Beach, Naples Beach and Atlantic Beach also have their advantages. Do Palm Beach and South Beach in Miami—if you are looking for a posh company or booming nightlife.
If you prefer more secluded and unspoilt locations, check out Blowing Rocks Preserve, Caladesi Island State Park at Caladesi Island or Canaveral National Seashore. Another hidden spot is the abandoned beach on the Boca Chica Key, a sandy unkempt spot for nude beach lovers (well, the sign says 'clothing optional beyond this point').