| Month | Daily minimum (°C) | Daily maximum (°C) | Days of rain | Rainfall (mm) |
|---|---|---|---|---|
| January | 13.6 | 21.7 | 7.8 | 25.4 |
| February | 13.9 | 21.8 | 6.8 | 24.8 |
| March | 12.8 | 20.6 | 9.8 | 31.6 |
| April | 11.0 | 18.8 | 14.0 | 55.0 |
| May | 9.1 | 16.4 | 17.6 | 77.6 |
| June | 7.6 | 14.5 | 19.5 | 97.3 |
| July | 6.7 | 13.8 | 21.6 | 104.5 |
| August | 7.1 | 14.5 | 20.7 | 94.6 |
| September | 8.1 | 15.8 | 17.7 | 66.7 |
| October | 9.3 | 17.5 | 15.3 | 52.2 |
| November | 10.8 | 18.9 | 11.5 | 38.4 |
| December | 12.3 | 20.3 | 10.1 | 34.6 |
| Statistics provided by BOM for Cape Northumberland (S.A.) (nearest comparable weather site to Nelson) | ||||