Frost dates in Seneca, IL
The average last spring frost in Seneca is around April 29 and the first fall frost is around October 17. That gives Seneca an average growing season of about 171 days.
Last spring frost
| Early (10% chance after) | April 3 |
|---|---|
| Average (50%) | April 29 |
| Late (90%) | May 16 |
First fall frost
| Early (10%) | October 6 |
|---|---|
| Average (50%) | October 17 |
| Late (90% chance before) | October 30 |