Florida experiences hot and humid summers. Moisture content can pave the way for microorganisms to assault your home's surfaces, so you'd have to pressure clean your house often to keep the spread of moss, mold, and mildew at bay.
This needs to be a yearly affair if you want to keep your house in pristine condition all year around. At least once a year, pressure cleaning your roof, driveways, patio, sidewalks, fences, garage, and pool decks, is advisable. You could do it after every six months if you have the budget for it. Otherwise, annual pressure cleaning should suffice as well.