Frost dates in Mattawa, WA
The average last spring frost in Mattawa is around April 2 and the first fall frost is around October 31. That gives Mattawa an average growing season of about 212 days.
Last spring frost
| Early (10% chance after) | March 8 |
|---|---|
| Average (50%) | April 2 |
| Late (90%) | April 21 |
First fall frost
| Early (10%) | October 17 |
|---|---|
| Average (50%) | October 31 |
| Late (90% chance before) | November 18 |