It’s been a long, cold winter. But it’s not the first (and it won’t be the last).
Photos below are from the Forest Products Laboratory roof, looking east.
Above you see a -37F degree day on January 30, 1951. Below is a similar shot taken during the (first) polar vortex of January 2014 [credit Steve Schmieding, FPL].
For a larger version of the 1951 image, visit our Flickr site.