You don’t know how deeply I tried to research not temperature but snowfall for those years. Called weather places, historical archives, observatories. Searching for some NY newspapers that would give weather reports like ours do now. I was researching the full moons and snowfall trying to pinpoint a likely creation date for Night Before Christmas. Family stories put it anywhere from 1805-1809 or so. I did fairly well on the moon, thanks to that website, but I died completely on NY snowfalls.