Frost dates in Castlewood, SD
The average last spring frost in Castlewood is around May 12 and the first fall frost is around October 5. That gives Castlewood an average growing season of about 146 days.
Last spring frost
| Early (10% chance after) | April 22 |
|---|---|
| Average (50%) | May 12 |
| Late (90%) | May 19 |
First fall frost
| Early (10%) | September 14 |
|---|---|
| Average (50%) | October 5 |
| Late (90% chance before) | October 15 |