Planning for the weather is a good way to make your trip to Dong Hoi relaxing and enjoyable, especially when you're splurging. The hottest months are usually June and July with an average temp of 83°F, while the coldest months are January and February with an average of 69°F. The rainiest months in Dong Hoi are October, September, November, and December, with each month seeing an average of 19 inches of rainfall.