The mountains to the west along with a significant influence of mild Pacific air cause Willits to have a cool winter and hot day/cool night summer climate. Average January temperatures range from to . Average July temperatures range from to . There are an average of 34.5 days with highs of 90 °F (32 °C) or higher, and an average of 80.3 days with lows of 32 °F (0 °C) or lower. The record maximum temperature was on June 30, 2005, and the record minimum temperature was on December 9, 1972.