| Month | Daily minimum (°C) | Daily maximum (°C) | Days of rain | Rainfall (mm) |
|---|---|---|---|---|
| January | 12.7 | 21.8 | 8.7 | 35.6 |
| February | 13.1 | 21.9 | 7.9 | 33.1 |
| March | 12.0 | 20.7 | 11.3 | 42.5 |
| April | 10.3 | 18.4 | 14.7 | 65.1 |
| May | 8.7 | 16.1 | 18.3 | 88.8 |
| June | 7.5 | 14.1 | 19.6 | 100.0 |
| July | 6.5 | 13.6 | 21.1 | 108.6 |
| August | 6.9 | 14.4 | 21.2 | 107.8 |
| September | 7.8 | 15.8 | 18.5 | 85.2 |
| October | 8.9 | 17.3 | 16.1 | 69.4 |
| November | 10.3 | 18.8 | 13.0 | 52.5 |
| December | 11.6 | 20.5 | 11.2 | 44.3 |
| Statistics provided by BOM for Portland (nearest comparable weather site to Portland) | ||||