Whiting can be found in the surf year round in Florida.  They do migrate seasonally as they follow water temperatures that suit them the best.  They will travel up part of the east coast and into the Gulf of Mexico as well.  The spring and fall will usually provide better fishing for whiting in the central and southern parts of Florida depending on water temperatures.  In the summer, they will be farther up north, so the fishing can change drastically based on the time of year.  Follow the fishing reports in your area.  When the whiting are around, you will hear about it.