First frost climatology, and does it have to be 32°?

Posted: Sep 19, 2023 / 05:53 PM EDT

Updated: Sep 20, 2023 / 10:27 AM EDT

SYRACUSE, NY (WSYR-TV)-

We are only a few days away from the official first day of Fall, and overnight lows will be dipping into the 40s more often over the coming nights, with even mid to upper 30s in the normally colder spots of CNY.

At this point there isn’t any concern of frost developing in the short term for most, but outside the normally colder spots south and east of Syracuse may see a touch of frost Wednesday night and Thursday night and possibly again next week.

This frost talk may have you wondering when the average first frost in Syracuse occurs and are there any signs that a frosty night coming up between now and the end of the month??

First frost climatology

So…the average date that Syracuse feels the low dip to 34 or 35 degrees or lower is October 9^th which often produces frost on the ground. The average first date of 32 degrees or lower isn’t until October 16^th.

Any frost potential this month?

Fortunately, there are no signs of frost potential in Central New York for at least the rest of the month the way it’s looking right now.

How does frost form when the temperature is above 32°?

How does frost develop when the temperature dips only to 34 or 35 degrees and not 32?

There are two important things to keep in mind. First, on cold nights the coldest air in the lower atmosphere will sink close to the ground because it is denser or heavier. Secondly, most outdoor thermometers are mounted several feet above where this coldest air settles.