September in Philipsburg is the hottest month of the year. In September, the weather in Philipsburg is typically hot. Average daily high temperature in September is about 29 degrees above zero. On average, Philipsburg has 13 rainy, 11 sunny, 5 partly cloudy, and 1 cloudy day in September. The rains are usually moderate. September as well as May, August, October, and November is considered the most uncomfortable time to visit Philipsburg.