Planning for the weather is a good way to make your trip to Vang Vieng relaxing and enjoyable, especially when you’re splurging. The hottest months are usually April and March, with an average temperature of 26°C, while the coldest months are January and December, with an average of 20°C. The rainiest months in Vang Vieng are August, July, September and June, with each month seeing an average of 369 mm of rainfall.