December in Rotorua is the cloudiest month of the year. In December, the weather in Rotorua is typically warm. Average daily high temperature in December is about 18 degrees above zero. On average, Rotorua has 20 rainy, 4 sunny, 4 partly cloudy, and 3 cloudy days in December. The rains are usually heavy. December as well as June, July, August, and September is considered the most uncomfortable time to visit Rotorua.