I just moved there about 3 years ago.
The Summers there are fairly hot, but not as miserable as Mississippi. The Fall can get quite rainy often and unexpectedly, so I always have an umbrella in my car.
The Winters are fairly mild. There isn't much snow. It will snow 3-4 times a year with only a few inches each time (if that). However, when it does snow (or any precipitation of any kind), citizens in Nashville get quite frantic. Traffic can be miserable over only a small amount of snow. The schools will can close at the mere mention of it.
It usually takes a while to warm up in the spring. The temperatures do not begin rising until April. Like the Fall, rain can be often yet unexpected in the Spring.