Planning for the weather is a good way to make your trip to Na Haeo relaxing and enjoyable, especially when you're splurging. The hottest months are usually April and March, with an average temperature of 28°C, while the coldest months are January and December, with an average of 22°C. The rainiest months in Na Haeo are August, September, July and May, with each month seeing an average of 270 mm of rainfall.