In September, the weather in Palmerston North is typically warm. Average daily high temperature in September is about 15 degrees above zero. On average, Palmerston North has 16 rainy, 7 sunny, 6 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as May, June, July, and August is considered the most uncomfortable time to visit Palmerston North.