Last time NYC had 100 degree in August (notably it was 103!) was on August 9, 2001, that's 24 years ago lol.
Last time JFK hit 100 degrees in August (they did so in both July and August in that year) was August 20, 1983. 1983 is on my list of all time summers, with a very hot June, July, August AND September (can't argue with 7 90 degree days in September including a peak of 99 on 9/11/1983 at NYC.)