Ashland lies within Oregon’s southwest interior climate zone, in which all but the higher-elevation sites are in the rain shadow of the Oregon Coast Range to the west. The largest urban areas in this zone in addition to Ashland are Medford and Grants Pass in the Rogue Valley, and Roseburg in the Umpqua River Valley further north. Although the mountain peaks in this zone receive up to 120 inches or 3,050 millimetres of precipitation a year, the urban areas and the valleys in which they lie generally get 20 inches .
The coolest month is December, with an average high temperature of 47 °F or 8.3 °C, and the warmest month is July, with an average high of about 88 °F or 31.1 °C. The highest temperature ever recorded in Ashland was 108 °F (42.2 °C), observed in August 1981, and the record low of −4 °F (−20 °C) occurred in December 1972. The wettest “rain year” has been from July 1926 to June 1927 with 29.77 inches (756.2 mm) and the driest from July 1954 to June 1955 with only 10.37 inches (263.4 mm). The wettest month on record has been December 1964 with 11.28 inches (286.5 mm), but the only other months with over 8 inches or 203.2 millimetres have been December 1996 with 10.89 inches (276.6 mm), November 1903 with 8.10 inches (205.7 mm) and November 1998 with 8.03 inches (204.0 mm).