Frost dates in Grafton, IL
The average last spring frost in Grafton is around April 10 and the first fall frost is around October 18. That gives Grafton an average growing season of about 191 days.
Last spring frost
| Early (10% chance after) | March 26 |
|---|---|
| Average (50%) | April 10 |
| Late (90%) | April 22 |
First fall frost
| Early (10%) | October 8 |
|---|---|
| Average (50%) | October 18 |
| Late (90% chance before) | November 2 |