Frost dates in Mount Vernon, IL
The average last spring frost in Mount Vernon is around April 14 and the first fall frost is around October 20. That gives Mount Vernon an average growing season of about 189 days.
Last spring frost
| Early (10% chance after) | March 31 |
|---|---|
| Average (50%) | April 14 |
| Late (90%) | April 30 |
First fall frost
| Early (10%) | October 4 |
|---|---|
| Average (50%) | October 20 |
| Late (90% chance before) | November 2 |