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.
No one cataloged snow falls in those days. It was winter and it snowed so no one really cared. Snow made travel and other activities more difficult. It wasn’t until Florida travel agents invented the phrase “partly sunny” that people began to care.