August in Wanaka is the rainiest and the cloudiest month of the year. In August, the weather in Wanaka is typically cold. Average daily high temperature in August is about 5 degrees above zero. On average, Wanaka has 12 rainy, 9 partly cloudy, 5 sunny, and 5 cloudy days in August. The rains are usually moderate. August as well as May, June, July, and September is considered the most uncomfortable time to visit Wanaka.