Weather will likely play an important role when you plan your trip to Viangxai, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June, with an average temperature of 23°C, while the coldest months are January and December, with an average of 15°C. The rainiest months in Viangxai are August, July, September and June, with each month seeing an average of 268 mm of rainfall.