First Freeze information for Chicagoland and the United States.

Earliest First Autumn Day at 32 Degrees
32°F on September 22, 1995

Earliest First Autumn Day below 32 Degrees
29°F on September 23, 1995

Latest First Autumn Day at 32°F or lower
November 24, 1931 was the latest first day to freeze at 32°F or lower when the low temperature reached 30°F.

The first freeze day occurrence average at Chicago’s O’Hare International Airport is October 13. This is the average day for a surprise early freeze, which is different than the average when you can expect the overnight/early morning low to reach 32°F on a regular basis.

The day of the year when the average temperature hits 32°F on a regular basis in the Fall season is November 15, 2015.

*Based on 1981-2010 Normal



According to the Farmer’s Almanac, a hard freeze is a period of at least four consecutive hours of air temperatures that are below 25 degrees Fahrenheit (-4°C). Many plants can survive a brief frost, but very few plants can survive a hard freeze.

SOURCE:
weather.gov/lot/firstfreeze

HOW TO PREDICT A FROST

See also …

NWS: Earliest, Latest and Average First Freeze Dates for North and Central Georgia

NWS: Northland Fall Freeze Dates: Duluth, MN, International Falls, MN, Brainerd, MN, Mellen, WI, Two Harbors, MN, Grand Marais, MN, Hibbing, MN

planthardiness.ars.usda.gov