Game viewing and Victoria Falls water levels
Because Zambia is a tropical country, it does not have a distinct summer and winter as such but rather a rainy and dry season. From November to March, there is a lot of rainfall and this means the national parks are lush and green. The game watching is not as good due to the plentiful water supply and the dense bush but the birding is spectacular. This time of year is also known as the Emerald Season, due to the bright green colours.
Game viewing is at its best from June onwards, during the dry season. September and October offer the optimal wilderness experience as animals congregate around waterholes, rivers and lakes. Having said that, game viewing is still pretty good all-year round and it often depends on what exactly you want to see.
Victoria Falls are at their most mighty in April and May, just after the rains have finished. In fact the Falls are the largest curtain of falling water in the world (when in full flood). In the dry season the levels may be lower but there is less spray so you have better panoramic views and you can explore the surroundings more fully.