Frost dates in Black Diamond, WA
The average last spring frost in Black Diamond is around May 4 and the first fall frost is around October 15. That gives Black Diamond an average growing season of about 164 days.
Last spring frost
| Early (10% chance after) | April 10 |
|---|---|
| Average (50%) | May 4 |
| Late (90%) | May 26 |
First fall frost
| Early (10%) | September 25 |
|---|---|
| Average (50%) | October 15 |
| Late (90% chance before) | November 4 |