Planning for the weather is a good way to make your trip to Oudomxay relaxing and enjoyable, especially when you're splurging. The hottest months are usually April and March, with an average temperature of 25°C, while the coldest months are January and December, with an average of 18°C. The rainiest months in Oudomxay are August, July, September and June, with each month seeing an average of 319 mm of rainfall.