 At the park headquarters , with an elevation of 3 @,@ 966 feet ( 1 @,@ 209 m ) , January averages 38 @.@ 2 ° F ( 3 @.@ 4 ° C ) , while July averages 73 @.@ 0 ° F ( 22 @.@ 8 ° C ) , though in summer the nights are much cooler than the hot days . There are an average of 39 @.@ 5 days with highs of 90 ° F ( 32 ° C ) or higher and an average of 97 @.@ 9 nights with freezing temperatures . Freezing temperatures have been recorded in every month of the year . The record high temperature was 115 ° F ( 46 ° C ) on July 20 , 1915 , while the record low temperature was − 6 ° F ( − 21 ° C ) on January 2 , 1924 and on January 21 , 1937 . Average annual precipitation is nearly 37 inches ( 940 mm ) , falling on 65 days . The wettest year was 1983 with 68 @.@ 94 inches ( 1 @,@ 751 mm ) and the driest year was 1976 with 14 @.@ 84 inches ( 377 mm ) . The most precipitation in one month was 29 @.@ 61 inches ( 752 mm ) in December 1955 and the most in one day was 6 @.@ 92 inches ( 176 mm ) on December 23 , 1955 . Average annual snowfall is 65 @.@ 6 inches ( 1 @.@ 67 m ) . The snowiest year was 1967 with 154 @.@ 9 inches ( 3 @.@ 93 m ) . The most snow in one month was 140 @.@ 8 inches ( 3 @.@ 58 m ) in January 1993 . 
