Grenada is around 12 degrees North, so very close to the equator. Old wisdom had it that Grenada was safe sailing grounds during hurricane season. Usually Hurricanes are rare the closer to the equator you get, but certainly hurricanes are possible, and recent history has changed our views on this supposed 'safe zone'. August is around peak time for hurricanes in the Caribbean. So, as long as you are prepared fully, and understand that you may need to get back to land in a hurry, and keep your eyes on the weather and receive weather reports at least three times a day, and never be more than 6 hours sailing away from a safe harbor, I would do it. But then we keep our eyes on the weather and we are safe sailors. If it was me, I would lay off the cocktails though.
It all depends on what kind of sailor you are and if you are prepared to run from weather. If you are doing a bare boat cruise, check in with your company at least 3 times a day. If you have a captain on board, ensure that he/she checks the weather at least three times a day. If anything is looming, get back to land pronto.
(Yes, yes, I know, not DR related...)