Frost dates in Groton, CT
The average last spring frost in Groton is around April 21 and the first fall frost is around October 30. That gives Groton an average growing season of about 192 days.
Last spring frost
| Early (10% chance after) | April 7 |
|---|---|
| Average (50%) | April 21 |
| Late (90%) | May 2 |
First fall frost
| Early (10%) | October 18 |
|---|---|
| Average (50%) | October 30 |
| Late (90% chance before) | November 9 |