subject: When & Why visit Johannesburg ? [print this page] Johannesburg winters are generally warm and dry with daytime temperatures reaching as high as 25C / 77F however the evenings are chilly and you may need a shawl or light jacket to cover you up. In a nut shell, best time to get Cheap Flights to South Africa is early Summer (September or October), second best is autumn (March to April) and stands third any time when you can get a cheap flight fare.