Frost dates in Lannon, WI
The average last spring frost in Lannon is around April 30 and the first fall frost is around October 17. That gives Lannon an average growing season of about 170 days.
Last spring frost
| Early (10% chance after) | April 21 |
|---|---|
| Average (50%) | April 30 |
| Late (90%) | May 14 |
First fall frost
| Early (10%) | October 4 |
|---|---|
| Average (50%) | October 17 |
| Late (90% chance before) | October 30 |