Frost dates in Castle Rock, CO
The average last spring frost in Castle Rock is around May 20 and the first fall frost is around September 24. That gives Castle Rock an average growing season of about 127 days.
Last spring frost
| Early (10% chance after) | April 28 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 10 |
First fall frost
| Early (10%) | September 13 |
|---|---|
| Average (50%) | September 24 |
| Late (90% chance before) | October 14 |