Lake McDonald in Glacier Park is Completely Frozen
Yeah, it's been pretty cold here in Montana. How old, you may ask? Well, how about this: it's so cold that Lake McDonald in Glacier Park is completely frozen over.
So yeah, that's pretty cold! I'm no scientist, but generally speaking, ice usually indicates that something is colder than it would normally be (but again, I'm no scientist).
Lake McDonald is the biggest lake in Glacier Park, and the last time it froze over was two years ago, during the winter of 2016-2017. Apparently, the ice is so clear that you can actually see the bottom in some places.