We've been end of march and april a couple of years. The weather is lovely, and depending on when you go, there are sometimes absolute herds of white and yellow butterflies that hover over the beach - they're really pretty, although the locals I think don't like them so much because they tend to get squashed on car windshields, etc....but since I'm not driving there, I can appreciate their beauty!!
We had the typical brief afternoon showers, but other than that, the weather was fabulous! Not too much humidity, and not overly overly hot either.
we have been to Swept Away in April the past 5 years. weather is warm to hot at times and just great. some afternoon rains on some trips. nothing to mention at all on others. it is all good mon. you will love being at Couples in April.