Georgetown
Saint Helena
| Season | Autumn | Winter | Spring | Summer | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Sep | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Year |
| Record high, °C | 27 | 28 | 28 | 30 | 30 | 30 | 31 | 32 | 31 | 30 | 28 | 27 | 32 |
| Average high, °C | 26 | 26 | 26 | 27 | 27 | 28 | 29 | 29 | 28 | 27 | 26 | 26 | 27 |
| Average temperature, °C | 24 | 24 | 24 | 25 | 26 | 26 | 27 | 27 | 26 | 26 | 25 | 24 | 25 |
| Average low, °C | 22 | 22 | 22 | 23 | 23 | 25 | 25 | 25 | 25 | 23 | 23 | 22 | 23 |
| Record low, °C | 15 | 16 | 20 | 18 | 21 | 20 | 22 | 22 | 20 | 21 | 17 | 18 | 15 |
| Rain, days | 13 | 13 | 15 | 11 | 9 | 7 | 10 | 9 | 8 | 10 | 11 | 12 | 128 |
| Average precipitation, mm. | 9 | 12 | 8 | 8 | 9 | 10 | 23 | 34 | 12 | 18 | 13 | 12 | 168 |
| Relative humidity morning, % | 76 | 76 | 80 | 79 | 81 | 81 | 81 | 79 | 76 | 74 | 73 | 75 | 78 |
| Relative humidity evening, % | 63 | 63 | 65 | 64 | 64 | 63 | 64 | 64 | 62 | 61 | 61 | 62 | 63 |
| Wind speed, km/h | 27 | 27 | 27 | 27 | 27 | 25 | 25 | 27 | 27 | 27 | 27 | 27 | 27 |
| Day Length, часов | 12 | 13 | 13 | 13 | 13 | 13 | 13 | 12 | 12 | 12 | 12 | 12 | 12 |
| Dew point, °C | 17 | 17 | 18 | 19 | 20 | 21 | 21 | 21 | 20 | 18 | 18 | 17 | 227 |
| Growing degree-day, °C | 417 | 431 | 417 | 465 | 482 | 439 | 517 | 500 | 482 | 467 | 465 | 431 | 5512 |
| Solar radiation, global, Mj/m2 | 21 | 22 | 22 | 24 | 26 | 27 | 26 | 24 | 22 | 20 | 20 | 21 | 23 |