Weather is probably a major factor when you plan your trip to Sanya Downtown, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually June and May, with an average temperature of 28°C, while the coldest months are January and December, with an average of 22°C. The rainiest months in Sanya Downtown are July, October, August and September, with each month seeing an average of 265 mm of rainfall.