Frost dates in Harrisburg, SD
The average last spring frost in Harrisburg is around May 9 and the first fall frost is around September 29. That gives Harrisburg an average growing season of about 143 days.
Last spring frost
| Early (10% chance after) | April 20 |
|---|---|
| Average (50%) | May 9 |
| Late (90%) | May 26 |
First fall frost
| Early (10%) | September 16 |
|---|---|
| Average (50%) | September 29 |
| Late (90% chance before) | October 17 |