wow that's amazing Don! 2/11/1966 meets what I was looking for, which is the largest gap in the winter where one is close to freezing. I believe that was just after a blizzard, as there was one around 2/11/1966? I wonder if there was a lot of snowcover on the ground that morning? Also do you have the largest gap where JFK was at or below freezing? Thanks!
That low of 74 at NYC on 4/17/2002 is startling....I remember the heatwave that month very well but didn't remember the huge gap in night time lows. Looks like another thing that heatwave had in common with the heatwave in April 1976!
I also remember the April 1991 period, as it was the earliest 90 degree day at NYC (until April 2010). Both were amongst our hottest summers.
I see the amazing March 1998 heat is up there, surprised the heat in March 1990 isn't.