The sun shines a lot in the Kalahari. In the tswana language, the word "pula' means "rain". But it also means "luck". The reserve receives a total annual rainfall of barely 250mm. The data below show average temperatures and hours of sunshine across the year so that you can see which are our luckiest months.
For up-to-date information on current weather conditions, click here. Be sure to search under the Upington region for Tswalu's forecast.
| Temp.Max | Temp.Min | Sunshine | Rainfall | Humidity | |
| C | C | Hrs/Day | mm/Month | %/Day | |
| Jan | 34.3 | 17.4 | 11.3 | 24 | 34 |
| Feb | 33.4 | 17.4 | 10.7 | 35 | 40 |
| March | 31.6 | 15.5 | 9.6 | 37 | 46 |
| April | 27.6 | 11 | 9.5 | 26 | 50 |
| May | 24 | 5.8 | 9.4 | 10 | 51 |
| June | 20.7 | 2.7 | 9 | 4 | 52 |
| July | 21 | 1.7 | 9.3 | 2 | 47 |
| Aug | 23 | 3.4 | 9.9 | 4 | 40 |
| Sep | 26 | 7.3 | 10 | 4 | 34 |
| Oct | 29 | 11 | 11 | 9 | 33 |
| Nov | 32 | 14 | 12 | 17 | 32 |
| Dec | 34 | 16 | 12 | 7 | 31 |
