The lowest temperature ever recorded in the city is 19.0 Â F ( â ' 7.2 Â C ) , on February 20 , 1955 , and the highest temperature ever recorded is 119.0 Â F ( 48.3 Â C ) , on June 26 , 1970 and August 2 , 1972 . The lowest temperature ever recorded in the city is 19.0 Â , on February 20 , 1955 , and the highest temperature ever recorded was 122.0 Â , on June 26 , 1990 .