October in Viljandi is the rainiest month of the year. In October, the weather in Viljandi is typically cold. Average daily high temperature in October is about 8 degrees above zero. On average, Viljandi has 18 rainy, 6 cloudy, 4 sunny, and 3 partly cloudy days in October. The rains are usually moderate. October as well as March and November is considered the most uncomfortable time to visit Viljandi.