Windsor experiences a semi-arid climate (Köppen "BSk"). High temperatures are generally around 85 °F (29 °C) in the summer and 42 °F (5 °C) in the winter, although there is significant variation. The hottest days generally occur in late July and the coldest in January. Nighttime lows are near 57 °F (14 °C) in the summer and around 15 °F (-9 °C) in the winter. Record high temperatures of 103 °F (39 °C) have been recorded, as have record low temperatures of -41 °F (-40 °C). The first freeze typically occurs around September 17, and the last often occurs in mid-May. The most precipitation typically occurs in May.