Been in Jan, Feb, March, April, May, June, Aug, Sept & Dec. Favorite time to be there is anytime we can be Actually, if I HAD to chose, it would be late Feb early March. Weather is just about perfect and the Eagle Rays are still around in numbers. Summer is very hot and humid and we've been eaten alive by mozzies on some trips. We're going next month (my wife's birthday is early Jan so that's a good excuse for a trip in my books) and crossing our fingers for no nortes. During the winter months, we always fly non-stop into and out of Cozumel - too many weather variables otherwise (coming from the great white north). In the summer, we often do the bag drag as their aren't many other options.