In over 30 years we have spent time in the Florida panhandle, Orlando area, Sarasota/Venice area, Key West, and most recently extended stays in Fort Myers.
In the panhandle between December to March, don't leave your sweatshirts and long britches at home because you will need them. Bring just one pair of shorts because you may or may not wear them once a week.
South of Sarasota, just bring shorts. If you don't enjoy being bitten by insects then use repellent. If you don't enjoy sunshine and warm weather, then refer to paragraph number 2.