Frost dates in Shannon City, IA
The average last spring frost in Shannon City is around April 22 and the first fall frost is around October 12. That gives Shannon City an average growing season of about 173 days.
Last spring frost
| Early (10% chance after) | April 9 |
|---|---|
| Average (50%) | April 22 |
| Late (90%) | May 12 |
First fall frost
| Early (10%) | September 28 |
|---|---|
| Average (50%) | October 12 |
| Late (90% chance before) | October 31 |