vr,
The Dutch Carnival takes place in the latter part of April and features parades and many other events in the Carnival Village. I don't know this years exact dates but I'm thinking you should be able to catch at least a parade or two. They are really something to see - all kinds of music and incredible costumes and dancing in the streets. Even if you don't plan on attending any events it would pay you to know what's happening when to avoid any additional traffic snafus.
The weather, as previously stated, is usually delightful - warm tropical breezes and very little rain, if any at all. Over the past 43 years we've probably spent at the very least 60+ April weeks on the island and I don't think we've experienced five rainy days total. Not to say it can't happen, but as a rule it's a pretty good time of year to be there.
We've also gone fairly regularly in late November into early December and most years we experience the occasional rainy day and generally breezier and near to windier days, enough so we're usually able to turn off the air o and let the breezes cool our condo.
In honesty, I don't think there's a bad time to be in SXM and since we'll be there in April also, I wish you beautiful sunny days - all of them! <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" /> <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />
We will be there April 14-19. Thank you!