From Channel Coastal Observatory graph showing temperature range by month for 2018-2020 data.
| Month | Degrees C |
| January | 6.7 |
| February | 6.1 |
| March | 7.6 |
| April | 9.7 |
| May | 12.6 |
| June | 16.2 |
| July | 18.4 |
| August | 19.9 |
| September | 17.6 |
| October | 14.3 |
| November | 9.9 |
| December | 7.7 |
Some data here on temperature rise. There are better figures for Sizewell somewhere. About 0.75 degrees C per decade.