Frost dates in St. Marys, PA
The average last spring frost in St. Marys is around May 10 and the first fall frost is around October 12. That gives St. Marys an average growing season of about 155 days.
Last spring frost
| Early (10% chance after) | April 16 |
|---|---|
| Average (50%) | May 10 |
| Late (90%) | May 24 |
First fall frost
| Early (10%) | September 29 |
|---|---|
| Average (50%) | October 12 |
| Late (90% chance before) | November 3 |