the weather for both months will be wonderful. Later in May will start to get hotter, but basically the weather is fine. early in April until the end of the third week there will still be lots of spring break people there. It starts to empty out a bit after the third week in the month. Also the rates in the hotels will probably go down around then as well. Easter is early in the month and it will be very crowded then. So, if you desire to avoid the crowds, I would say that the end of April or beginning of May would be the best.