Isla Mujeres in November

December through April delivers the island's best weather. Temperatures hover around 80°F with minimal rainfall and steady trade winds that keep things comfortable. This is peak season, so expect higher prices and crowded beaches. May and November offer sweet spots for weather and crowds. Temperatures climb into the mid-80s, but afternoon showers cool things down. Hotel rates drop 30-40% compared to peak season. June through September brings whale shark season — the main reason to brave the heat and humidity. Temperatures hit 90°F regularly, and afternoon thunderstorms roll through most days. But swimming with whale sharks makes the sweat worth it. Avoid October unless you're comfortable with hurricane risk. The island sits directly in the storm path, and several hotels close for the month. September can be dicey too, though many years pass without major storms. Christmas and Easter weeks see the biggest crowds and highest prices. Book accommodations six months ahead for these periods.