September in Oklan is the rainiest month of the year. In September, the weather in Oklan is typically cold. Average daily high temperature in September is about 7 degrees above zero. On average, Oklan has 16 rainy, 6 cloudy, 5 sunny, and 3 partly cloudy days in September. The rains are usually moderate. September as well as January, February, March, and May is considered the most uncomfortable time to visit Oklan.