The consensus among travel experts is that March through May is the best time to visit Key West. During these months, the winter crowds have started to thin out, and the sweltering humidity of the summer hasn't yet arrived. Temperatures are nearly perfect, hovering in the mid-70s to low-80s, and rainfall is minimal. March is particularly popular for "winter sun" seekers, while May offers a great "shoulder season" balance of lower hotel prices and lively local events. If you are looking for the absolute lowest prices, the hurricane season months (August to October) are cheapest, but you risk stormy weather and extreme heat. For those who enjoy festive atmospheres, December and January are beautiful but can be quite expensive and crowded as people flock south to escape the northern chill.