March in Grants Pass is the rainiest and the windiest month of the year. In March, the weather in Grants Pass is typically warm. Average daily high temperature in March is about 10 degrees above zero. On average, Grants Pass has 21 rainy, 6 cloudy, and 4 sunny days in March. The rains are usually heavy. March as well as January, February, April, and November is considered the most uncomfortable time to visit Grants Pass.