Johannesburg
South Africa
| Season | Autumn | Winter | Spring | Summer | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Sep | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Year |
| Average high, °C | 26 | 26 | 27 | 28 | 28 | 28 | 27 | 26 | 25 | 23 | 23 | 24 | 26 |
| Average temperature, °C | 18 | 20 | 21 | 22 | 23 | 23 | 22 | 19 | 17 | 14 | 14 | 16 | 19 |
| Average low, °C | 11 | 14 | 16 | 17 | 18 | 18 | 17 | 14 | 9 | 6 | 6 | 8 | 13 |
| Average precipitation, mm. | 31 | 73 | 111 | 136 | 124 | 122 | 92 | 56 | 18 | 13 | 12 | 13 | 802 |
| Relative humidity, % | 59 | 63 | 68 | 69 | 70 | 71 | 72 | 70 | 64 | 60 | 58 | 58 | 65 |
| Wind speed, km/h | 8 | 8 | 7 | 7 | 7 | 6 | 5 | 5 | 5 | 5 | 6 | 7 | 6 |
| Day Length, часов | 12 | 13 | 14 | 14 | 14 | 13 | 13 | 13 | 11 | 11 | 11 | 12 | 13 |
| Dew point, °C | 10 | 12 | 15 | 16 | 17 | 17 | 17 | 14 | 10 | 6 | 6 | 8 | 146 |
| Growing degree-day, °C | 237 | 295 | 321 | 378 | 397 | 359 | 369 | 279 | 202 | 105 | 115 | 177 | 3232 |
| Solar radiation, global, Mj/m2 | 19 | 19 | 20 | 21 | 22 | 21 | 19 | 17 | 15 | 14 | 15 | 17 | 18 |