In May, the weather in Palmerston North is typically warm. Average daily high temperature in May is about 12 degrees above zero. On average, Palmerston North has 14 rainy, 7 sunny, 7 partly cloudy, and 3 cloudy days in May. The rains are usually moderate. May as well as June, July, August, and September is considered the most uncomfortable time to visit Palmerston North.