The white bass run should last from May to December. The white bass in the Mississippi and Ohio Rivers primarily feed on shad, which spawn during the period of March through September, this river migration peaks in June. When the water temperature rises to 54 degrees Fahrenheit or more, it stimulates a biological process called gonadal maturation triggering male and female fish to migrate downstream. By November, as water temperatures start cooling again below 54 degrees Fahrenheit they have all but disappeared by winter's time due to lack of available food sources.