Yalong Bay is a year-round destination thanks to Hainan's tropical climate, but the seasons matter for crowds and weather.
October to April is high season — warm, dry, low humidity, with daytime temperatures around 26–30°C. The Chinese New Year week (late January or early February) is the busiest stretch of the year, when rooms triple in price and the beach fills with families. Book months ahead.
May to September is the wet season, hot and humid (32–35°C, with afternoon thunderstorms most days). July and August carry typhoon risk, though Yalong's south-facing position offers some shelter. The trade-off is sharply cheaper rates and far fewer people. The bay is at its emptiest in early June and late September.
Avoid the Chinese national holidays in early May (Labour Day) and early October (National Day), when domestic tourism spikes and prices follow.