Interesting - I have new Davis Vue that seems to be exceptionally accurate. After I posted my obs, I saw that MU was also 53. Not sure why all of those places you listed were so much cooler. Anywho, 55.2 here now.
Edit: It's 55 at MDT as of their latest obs. We are right with each other...
Edit #2: It's actually 53 at HIA...my mistake. That was 45 minutes ago.