Frost dates in Grass Valley, OR
The average last spring frost in Grass Valley is around May 10 and the first fall frost is around October 5. That gives Grass Valley an average growing season of about 148 days.
Last spring frost
| Early (10% chance after) | April 21 |
|---|---|
| Average (50%) | May 10 |
| Late (90%) | May 28 |
First fall frost
| Early (10%) | September 19 |
|---|---|
| Average (50%) | October 5 |
| Late (90% chance before) | October 25 |