Frost dates in Riverton, WY
The average last spring frost in Riverton is around May 20 and the first fall frost is around September 17. That gives Riverton an average growing season of about 120 days.
Last spring frost
| Early (10% chance after) | May 3 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 9 |
First fall frost
| Early (10%) | September 5 |
|---|---|
| Average (50%) | September 17 |
| Late (90% chance before) | October 3 |