Frost dates in Savanna, IL
The average last spring frost in Savanna is around May 9 and the first fall frost is around October 1. That gives Savanna an average growing season of about 145 days.
Last spring frost
| Early (10% chance after) | April 22 |
|---|---|
| Average (50%) | May 9 |
| Late (90%) | May 26 |
First fall frost
| Early (10%) | September 18 |
|---|---|
| Average (50%) | October 1 |
| Late (90% chance before) | October 17 |