ROCKFORD, Ill. (WTVO) — Chilly air is already blasting Illinois with 30-degree temperatures and early-morning frost, meaning snowfall isn’t far behind.

So, when can you expect to see snow for the first time this season? Another month on average, according to the University of Illinois.

The northern part of Illinois tends to experience its first snowfall around Thanksgiving, according to data collected from 1971-2000.

However, we have officially entered historic snowfall territory. Data from the National Weather Service (NWS) says the earliest measurable (0.1 inches or more) snowfall in Rockford occurred on October 12, 1928. The “normal first date” of measurable snowfall in Rockford is November 20.

Rockfordians in 1940 had to wait until the new year to see snow. The latest measurable snowfall ever recorded occurred on January 7 of that year.

NWS data shows snowfall tends to begin around mid-to-late October. It may not happen this week, but we could see a few flakes any time now.