Frost dates in Decatur, IL
The average last spring frost in Decatur is around April 20 and the first fall frost is around October 17. That gives Decatur an average growing season of about 180 days.
Last spring frost
| Early (10% chance after) | April 7 |
|---|---|
| Average (50%) | April 20 |
| Late (90%) | May 9 |
First fall frost
| Early (10%) | October 1 |
|---|---|
| Average (50%) | October 17 |
| Late (90% chance before) | November 1 |