Frost dates in Royal, IL
The average last spring frost in Royal is around April 20 and the first fall frost is around October 23. That gives Royal an average growing season of about 186 days.
Last spring frost
| Early (10% chance after) | April 7 |
|---|---|
| Average (50%) | April 20 |
| Late (90%) | May 4 |
First fall frost
| Early (10%) | October 9 |
|---|---|
| Average (50%) | October 23 |
| Late (90% chance before) | November 6 |