You have an excellent chance of seeing lots of wildlife in Zambia during the Dry season (May to October). This will fit in nicely with a visit to Victoria Falls, which is at its best from June to September. A Wet season safari (November to April) is much more challenging, as most parks and camps shut down because of heavy rain. The Mfuwe section of South Luangwa NP is an exception: you can drive its all-weather roads year-round.
May to October –Dry Season – Winter
Wildlife Photos

November to April –Wet Season – Summer
Wildlife Photos
Best Time to Go to Zambia by Major Park
For the best wildlife viewing in the main parks, visit in the dry winter months (May to October). This coincides with the best opportunities for great photos of Victoria Falls – between May and August. Most camps close in the rainy season and washed-out roads makes travel difficult. However, the landscape is beautiful and bird watching is superb at this time.