Florence Municipal Airport (FMU) does not have a lounge, and the reason is simple: this Oregon coast field serves general aviation rather than scheduled airline traffic, so there is no passenger terminal built around boarding queues or connections in the way a commercial lounge would need. If you searched Florence airport lounge expecting a Priority Pass style room, the honest answer is that no such facility exists at this field, and none is likely to appear while it remains a general aviation airport.
The reason ties directly to what kind of airport Florence Municipal actually is. It supports private aircraft, flight training, and occasional charter traffic along the central Oregon coast, not the scheduled jet service that creates demand for a lounge in the first place. Airports without recurring commercial flights simply do not build or lease lounge space, because there is no membership base, no airline club, and no card-network contract to support one. Florence itself is known for the nearby Oregon Dunes and Sea Lion Caves, destinations most visitors reach by car rather than by air, which reinforces why the local airport was never built around passenger flow.
For travelers near Florence who want an actual lounge experience, the realistic option is Eugene Airport (EUG), Mahlon Sweet Field, roughly sixty miles inland, which handles scheduled commercial service and the kind of passenger volume that supports airline and card-network lounges. Eugene is the practical starting point if a pre-flight lounge matters to your trip, rather than expecting anything at Florence itself.
If you are flying privately out of Florence Municipal, general aviation terminals of this kind typically offer a small waiting area and pilot facilities rather than a commercial lounge, and that is unlikely to change. Anyone connecting through the region for a commercial flight should plan their lounge expectations around Eugene, checking that airport's current airline and lounge listings before travel, since Florence itself will not factor into that part of the trip.