Planning for the weather is an important factor for making your trip to Hpa-An a success, especially when you’re splurging. The hottest months are usually April and March with an average temp of 83°F, while the coldest months are January and February with an average of 79°F. The rainiest months in Hpa-An are July, August, June, and September, with each month seeing an average of 34 inches of rainfall.