Great Barrier Reef in March

April through October offers the reef's sweet spot – dry weather, calm seas, and water temperatures perfect for extended snorkeling. May and June are particularly magic. The trade winds haven't kicked in yet, so boat rides stay smooth, and you're between the summer humidity and winter crowds. Water visibility peaks during these months, often exceeding 30 meters at outer reef sites. July through September brings the busiest period and highest accommodation prices, but also the most reliable weather. Stinger season runs October through May, when box jellyfish and irukandji make swimming impossible without protective suits. Most tour operators provide stinger suits during this period, but they're hot and restrictive. The wet season from December to March means afternoon thunderstorms, rough seas, and tour cancellations. But here's the upside: accommodation prices drop 30-40%, and you'll have popular snorkel sites nearly to yourself on clear days. Cyclone season peaks January through March, so check weather forecasts obsessively if visiting then.