Weather is probably a major factor when you plan your trip to Dongshan, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August with an average temp of 82°F, while the coldest months are January and February with an average of 64°F. The rainiest months in Dongshan are October, June, August, and September, with each month seeing an average of 16 inches of rainfall.