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
— The Weather Channel (@weatherchannel) September 26, 2018
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.
See also …