Frost dates in St. Charles, ID
The average last spring frost in St. Charles is around May 20 and the first fall frost is around September 17. That gives St. Charles an average growing season of about 120 days.
Last spring frost
| Early (10% chance after) | May 3 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 10 |
First fall frost
| Early (10%) | September 7 |
|---|---|
| Average (50%) | September 17 |
| Late (90% chance before) | October 5 |