March in Knoxville is the rainiest month of the year. In March, the weather in Knoxville is typically warm. Average daily high temperature in March is about 14 degrees above zero. On average, Knoxville has 12 rainy, 11 partly cloudy, and 8 sunny days in March. The rains are usually moderate. March as well as January, February, and December is considered the most uncomfortable time to visit Knoxville.