I dug a little deeper for DCA. Counts by month (the count is higher than the period of record because of ties):
March: 1 (1907)
April: 2 (1960, 1976)
May: 4 (1889, 1963, 1996, 2004)
June: 35
July: 83
August: 42
September: 13
October: 0 (In 2019 DCA was one degree away with 98 in October, the annual high was 99)