Tropical weddings are usually humid and you have to dress accordingly. Remember, to always be a little dressier to be on the safe side. If you're not sure if what you're planning to wear is dressy enough, it's probably not. Upgrade it a notch and you're certain to be just fine. As with a casual wedding, look for cotton sundresses and nice sandals or wedges. If the wedding is being held outside and the weather is blazing, consider topping the look off with a sunhat.