The best time depends on where you are going, what you want to see, weather preferences, crowds and budget. A month that is ideal in one region may not be ideal in another.
Dry-season wildlife concentration is only one factor. Green seasons can bring beautiful landscapes, young animals and different pricing.
Peak periods can be excellent for wildlife but busier and more expensive.
If your travel window is fixed, I work backward from those dates rather than forcing a generic “best month.”
Tell me what you have in mind and what matters most to you.