Frost dates in Mount Vernon, SD
The average last spring frost in Mount Vernon is around May 3 and the first fall frost is around October 6. That gives Mount Vernon an average growing season of about 156 days.
Last spring frost
| Early (10% chance after) | April 13 |
|---|---|
| Average (50%) | May 3 |
| Late (90%) | May 15 |
First fall frost
| Early (10%) | September 24 |
|---|---|
| Average (50%) | October 6 |
| Late (90% chance before) | October 17 |