1966 and 2010 were both at 100 or above (2010 a little hotter than NYC, 1966, was significantly hotter than NYC.) Some of those other periods were really long, an 8 day heatwave in 2013 which peaked at 100 (hotter than NYC) 2006 had a 7 day heatwave that I don't even remember that peaked at 99 wow. 1993's 7 day heatwave that peaked at 101 I remember well and also 1999's 5 day heatwave that peaked at 102. And 1983's 6 day heatwave that peaked at 100 which was our previous hottest summer prior to 2010.