Frost dates in McHenry, IL
The average last spring frost in McHenry is around April 28 and the first fall frost is around October 11. That gives McHenry an average growing season of about 166 days.
Last spring frost
| Early (10% chance after) | April 20 |
|---|---|
| Average (50%) | April 28 |
| Late (90%) | May 15 |
First fall frost
| Early (10%) | October 1 |
|---|---|
| Average (50%) | October 11 |
| Late (90% chance before) | October 24 |