The periods below are how this park actually divides its year, with thirty-year climate averages against each month. Averages hide bad years: a dry January still happens, and so does a wet July.
The rhythm of the valley
The Luangwa is one of the last major unaltered rivers in southern Africa: no dams, no serious abstraction. It floods through the rains from November to March, then drops hard, and as it shrinks the game piles onto whatever water is left. That is the dry-season spectacle, and it peaks in September and October.
Two myths worth clearing up before you plan. The park does not close in the rains, most of the bush camps do, roughly mid-January to mid-March. And flights to Mfuwe run all year, just less often.