Planning for the weather is an important factor for making your trip to Nantou a success, especially when you’re splurging. The hottest months are usually July and August, with an average temperature of 26°C, while the coldest months are January and February, with an average of 18°C. The rainiest months in Nantou are August, June, July and May, with each month seeing an average of 378 mm of rainfall.