| Month | Daily minimum (°C) | Daily maximum (°C) | Days of rain | Rainfall (mm) |
|---|---|---|---|---|
| January | 12.9 | 23.8 | 7.5 | 49.3 |
| February | 13.2 | 24.6 | 6.7 | 45.8 |
| March | 12.1 | 22.5 | 9.2 | 61.0 |
| April | 10.2 | 19.5 | 12.0 | 78.5 |
| May | 8.5 | 16.7 | 14.7 | 97.5 |
| June | 6.6 | 14.2 | 15.4 | 96.2 |
| July | 6.1 | 13.5 | 16.6 | 98.7 |
| August | 6.7 | 14.4 | 16.7 | 101.8 |
| September | 7.6 | 15.9 | 14.9 | 89.8 |
| October | 8.7 | 18.0 | 13.7 | 87.8 |
| November | 10.1 | 19.7 | 11.0 | 69.1 |
| December | 11.5 | 21.7 | 9.4 | 60.1 |
| Statistics provided by BOM for Wonthaggi (nearest comparable weather site to Grantville) | ||||