I fly out of Jfk multiple times a week for close to 20 years.
It has its own weather separate from NYC for two reasons:
Near the southern shore
Removed from the UHI with lots of grassy open space in and around it
it is more representative of Central and southern Long Island, and can be much cooler in the summer or warmer in the winter than nearby LGA. on nights with radiational cooling, it also cools much quicker than LGA.
This particularly affects snowfall: very often rain, or on the heavier end of snow for coastal storms.
in an a city, where everything land wise is small, JFK is the size of Manhattan from the Battery all the way up into the 100s. as a result, it has a different weather environment.
On another note, but similar, 19° in Westchester this morning I drove down to LaGuardia 32°.
I’m a similar distance from Midtown Manhattan that JFK is. My snowfall and my temperatures are not representative of Central Park in anyway.