Frost dates in Ontario, CA
The average last spring frost in Ontario is around February 3 and the first fall frost is around December 16. That gives Ontario an average growing season of about 317 days.
Last spring frost
| Early (10% chance after) | January 12 |
|---|---|
| Average (50%) | February 3 |
| Late (90%) | February 25 |
First fall frost
| Early (10%) | November 28 |
|---|---|
| Average (50%) | December 16 |
| Late (90% chance before) | December 27 |