Weather is probably a major factor when you plan your trip to Ha Giang, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June with an average temp of 70°F, while the coldest months are January and December with an average of 53°F. The rainiest months in Ha Giang are August, July, June, and September, with each month seeing an average of 8 inches of rainfall.