Frost dates in Superior, WI
The average last spring frost in Superior is around May 12 and the first fall frost is around September 29. That gives Superior an average growing season of about 140 days.
Last spring frost
| Early (10% chance after) | April 28 |
|---|---|
| Average (50%) | May 12 |
| Late (90%) | June 9 |
First fall frost
| Early (10%) | September 13 |
|---|---|
| Average (50%) | September 29 |
| Late (90% chance before) | October 19 |