Frost dates in Petersburg, IL
The average last spring frost in Petersburg is around April 20 and the first fall frost is around October 27. That gives Petersburg an average growing season of about 190 days.
Last spring frost
| Early (10% chance after) | March 30 |
|---|---|
| Average (50%) | April 20 |
| Late (90%) | April 24 |
First fall frost
| Early (10%) | October 11 |
|---|---|
| Average (50%) | October 27 |
| Late (90% chance before) | November 2 |