huh, I lived through the 90s I know how hot they were, the heat was unbearable. Particularly in 1993, it forced me to install air conditioning for the first time in my life. I didn't even use air conditioning in 1988 (which you cite as the hottest.) That three day heatwave in early July 1993 was something I had NEVER experienced before.
4 straight days of 100+ at EWR
3 straight days of 100+ at NYC
2 straight days of 100+ at JFK
NYC three straight days of 100, 101, 102 were something I had never seen before, EWR even hit their all time record high of 105 twice in that period.
I don't think they were defective, rather the NYC ASOS being used now is very poorly sited, but even otherwise, that kind of long duration extreme heatwave has not been equaled since.