It depends on the Basement, generally they don't flood there, but there may be some ground water seeping in. Lakewood is the worst street for that.

As far as water coming down the sidewalk and into the basement door, it's usually not a problem as long as the bottom of the stairs has a drain to your sump. But if it is a problem for heavy rains, it seems like 3-6 sandbags would be an easy solution.