While widespread frost is not expected tonight, there could certainly be scattered areas of frost. This is especially true for open, unsheltered areas. If you have any especially tender vegetation that you want to protect, I’d certainly protect it tonight.
Overnight lows are expected to drop into the low to mid 30s. The dewpoint is already 29 degrees, which means temps could easily drop into the lower 30s tonight.
A frost advisory is currently not in effect for Cumberland or Fentress counties but there are advisories just to our east in Morgan and Scott counties (issued by NWS Morristown). All the counties in eastern Kentucky are under frost advisories too. I’ve often seen the Nashville NWS wait until we’re late into the night before issuing a frost advisory for us. That doesn’t help you much if you had intended to protect something before going to bed.
Dogwood winter is right on schedule! You all stay warm!