What's the weather like in Haikou and Sanya now? The most important thing is what clothes to wear. The more detailed, the better.

The weather has obviously warmed up recently. The temperature in Haikou is around 17~27 degrees, and in Sanya it is between 20~28 degrees. So you can wear a T-shirt during the day, and you need to add a coat sooner or later. But in cold air, you should wear a thick coat or sweater. Like the cold air a few days ago, the minimum temperature dropped to 10 degrees, which was quite cold. So I suggest that you mainly bring clothes in spring and autumn (thin long-sleeved short-sleeved T-shirt and thin coat), and then bring autumn trousers, a sweater or two, and a thick coat that is warm enough. Because if there is cold air or rain, it will be very cold indoors, but it will be fine outdoors.