Andy, it's a failing temperature and dewpoint sensor at that particular station. I've seen that several times at other sites, and it wouldn't surprise me if the extreme heat has something to do with it. Since it's an AWOS (cheaper and not as accurate as an ASOS, which the NWS does maintain), they can't do anything except call someone to notify the FAA about it unless the sensor magically fixes itself when it cools down tonight.