Frost dates in St. Helens, OR
The average last spring frost in St. Helens is around April 18 and the first fall frost is around October 31. That gives St. Helens an average growing season of about 196 days.
Last spring frost
| Early (10% chance after) | March 15 |
|---|---|
| Average (50%) | April 18 |
| Late (90%) | May 26 |
First fall frost
| Early (10%) | October 14 |
|---|---|
| Average (50%) | October 31 |
| Late (90% chance before) | November 26 |