We went from Mid-May to the first part of June 2 years ago. The weather was perfect! Cool in morning and evening and shirt sleeves by about 10AM. No rain. We went on the Ultimate Africa tour by OAT (Overseas Adventure Travel). We had an excellent experience and would use them again. We also did our own side trip to Cape Town for a few days - it's worth it since your're in the neighborhood. The trip was the best thing we have ever done. The guides are phenominal in their knowledge and the food was good.