Frost dates in Simpson, IL
The average last spring frost in Simpson is around April 11 and the first fall frost is around October 18. That gives Simpson an average growing season of about 190 days.
Last spring frost
| Early (10% chance after) | March 23 |
|---|---|
| Average (50%) | April 11 |
| Late (90%) | April 25 |
First fall frost
| Early (10%) | October 5 |
|---|---|
| Average (50%) | October 18 |
| Late (90% chance before) | November 2 |