August in Rotorua is the rainiest month of the year. In August, the weather in Rotorua is typically warm. Average daily high temperature in August is about 10 degrees above zero. On average, Rotorua has 20 rainy, 6 sunny, 3 partly cloudy, and 2 cloudy days in August. The rains are usually heavy. August as well as June, July, September, and October is considered the most uncomfortable time to visit Rotorua.