Standard broadcast FM stations can be heard 800 to a thousand miles away via a propagation mode known as thermal ducting. This is where a layer of cold air gets sandwiched between two layers of warm air. This is somewhat rare, and usually doesn't last very long. Sporadic E can also sometimes cause FM stations to be heard at great distances also.
We, as amateurs, love this kind of stuff, but professional broadcast engineers view these events as nuisance propagation, and they adjust antenna patterns to avoid it, to the extent possible.