Planning for the weather is a good way to make your trip to Viet Yen relaxing and enjoyable, especially when you're splurging. The hottest months are usually June and July, with an average temperature of 29°C, while the coldest months are January and December, with an average of 19°C. The rainiest months in Viet Yen are August, July, May and June, with each month seeing an average of 303 mm of rainfall.