Generally speaking, you want to plant grass in the fall or early spring. The grass needs time to sprout and get some growth before hot weather.

Up here, and esp in KY I'd say go with a 'cool-season' grass, like tall fescue. Warm season grasses like zoysia and bermuda are great for summer droughts, but are brown all winter and half-way into spring. Plus as a gardener, I think they're a nightmare beyond words they way they creep into beds. You'll need to amend your soil to keep the grass healthy.

Another option. When we first moved onto our property it was barren, so we planted white clover and were very pleased with how well it grew, stayed green throughout the summer and was remarkable drought tolerant. Bonus: blooms that attracted butterflies and bees. In the fall we seeded out grass into the clover lawn and it did quite well.

One last thing, you'll double your chances of success if you plant grass in the fall VS spring.

Here are some links that I think you'll find very helpful...

Here is a link that might be useful: UT Extension Publication PB1576: Fescues

...another link...

Here is a link that might be useful: UT Extension Publication PB1038: Lawn Management