Frost dates in Thermopolis, WY
The average last spring frost in Thermopolis is around May 14 and the first fall frost is around September 24. That gives Thermopolis an average growing season of about 133 days.
Last spring frost
| Early (10% chance after) | April 27 |
|---|---|
| Average (50%) | May 14 |
| Late (90%) | June 9 |
First fall frost
| Early (10%) | September 9 |
|---|---|
| Average (50%) | September 24 |
| Late (90% chance before) | October 14 |