| Month | Daily minimum (°C) | Daily maximum (°C) | Days of rain | Rainfall (mm) |
|---|---|---|---|---|
| January | 15.0 | 23.3 | 9.2 | 41.0 |
| February | 15.7 | 24.2 | 7.4 | 42.0 |
| March | 14.3 | 22.1 | 10.3 | 33.8 |
| April | 12.2 | 19.1 | 13.3 | 63.5 |
| May | 10.5 | 16.1 | 16.2 | 68.0 |
| June | 8.8 | 13.8 | 16.2 | 61.6 |
| July | 8.1 | 13.2 | 17.7 | 61.5 |
| August | 8.3 | 14.3 | 17.9 | 74.5 |
| September | 9.2 | 15.8 | 16.5 | 69.8 |
| October | 10.3 | 17.5 | 15.1 | 63.6 |
| November | 11.9 | 19.5 | 11.3 | 57.1 |
| December | 13.4 | 21.4 | 9.8 | 37.4 |
| Statistics provided by BOM for Rhyll (nearest comparable weather site to Cowes) | ||||