October Weather in Mara: good for safari?

Hi,

What will be the weather in Masai Mara be like this October? We are from India and have been informed of the forecasts, which predict heavy rains starting from October. As we will be doing our safari in the Mara this Oct beginning, we like to know what the chances are of seeing the Big Five & the Migrating animals and whether rains would play spoilsport. We are also travelling to Serengeti, for your information.

Any help?

Thanks.