Frost dates in Castle Rock, WA
The average last spring frost in Castle Rock is around April 20 and the first fall frost is around November 2. That gives Castle Rock an average growing season of about 196 days.
Last spring frost
| Early (10% chance after) | March 19 |
|---|---|
| Average (50%) | April 20 |
| Late (90%) | May 15 |
First fall frost
| Early (10%) | October 10 |
|---|---|
| Average (50%) | November 2 |
| Late (90% chance before) | November 25 |