Frost dates in Harrisburg, OR
The average last spring frost in Harrisburg is around April 20 and the first fall frost is around October 21. That gives Harrisburg an average growing season of about 184 days.
Last spring frost
| Early (10% chance after) | March 16 |
|---|---|
| Average (50%) | April 20 |
| Late (90%) | May 12 |
First fall frost
| Early (10%) | October 4 |
|---|---|
| Average (50%) | October 21 |
| Late (90% chance before) | November 18 |