What's causing JFK to be warmer than NYC, is it because of Jamaica Bay (although the wind trajectory isn't coming off the bay?) This isn't a radiational cooling night, with the wind, and JFK is usually colder when there is good radiational cooling.
Is this why LGA typically has the latest freeze? It seems like its lows are always higher than the rest of the region, no matter the time of the year and no matter the wind direction
Weird thing about JFK is with offshore flow during the summer they are usually just as hot as EWR is and hotter than either NYC or LGA, I've always wondered of the buildings to the north and west of JFK actually create a downslope effect lol. I noticed that happens in the winter too, but it's less noticeable because NW winds are cold winds in the winter, but JFK still manages to be milder than the other official locations. It's usually a 2-3 degree difference.