This is usually the time of year that we record the first below zero low temperatures of the season. It is also no coincidence that this is also the time of year when we began to record our first snowfalls of one inch or greater. Like most other climate statistics, the first below zero reading varies greatly from year to year.
The earliest below zero low temperature occurred on October 26, 1919 when the low dropped to -4 degrees. The latest first negative of the season was back in 1987 when our first negative temperature did not occur until December 31. The average date is sandwiched in between those two extremes on November 28. The average last below zero day in spring is on March 11.
The overall average number of days below zero during our cold season is 48, with ten of those days recording both a negative high and low.