If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Tay Ninh: The hottest months are usually March and April with an average temp of 85°F, while the coldest months are January and December with an average of 81°F. The rainiest months in Tay Ninh are September, October, July, and August, with each month seeing an average of 12 inches of rainfall.