This depends on what you are looking for on a vacation. The Winter and Spring months are the most popular because the weather is simply perfect. The downside being that the price of your vacation rental and everything else is significantly more expensive ~ Supply & Demand!
On the other hand, if you are looking to save money and come visit during the slower months, come anytime after the Easter holiday. The prices are much lower and town is much quieter; downside being that it’s HOT and HUMID during the summer months.
If you want the best of both, I recommend visiting end of April and May, October, November or December before the Holiday season; the weather is cooler and the crowds are much quieter!