Table 18. Monthly and annual average and extreme heating degree days (HDD) for CFA(a). Daily Extremes Average Highest Lowest Highest Lowest (HDD) (HDD) (HDD) (HDD) (HDD) January 1,504 1,828 1,086 85 22 February 1,227 1,623 865 88 20 March 1,023 1,446 728 71 10 April 683 889 471 44 2 May 417 623 206 35 0 June 174 305 38 26 0 July 26 192 0 16 0 August 47 192 0 20 0 September 270 493 100 36 0 October 658 955 433 55 0 November 1,059 1,342 860 74 8 December 1,446 1,799 1,181 93 18 ANNUAL 8,533 10,268 7,524 93 0 a. Data period of record spans January 1950 through December 2021.