Frost dates in Glen Ullin, ND
The average last spring frost in Glen Ullin is around May 20 and the first fall frost is around September 20. That gives Glen Ullin an average growing season of about 123 days.
Last spring frost
| Early (10% chance after) | May 8 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 3 |
First fall frost
| Early (10%) | September 5 |
|---|---|
| Average (50%) | September 20 |
| Late (90% chance before) | October 7 |