Quite a few folks are searching for this information on our site. From what I can gather, Reagan National saw 0.6″ (I saw same in Eisenhower East), parts of West End in Alexandria saw 1.5″, Dulles 2″, BWI: 1″. With parts of Fairfax clocking in over 4″.
Capital Weather Gang has a complete roundup of snowfall totals at this link.
News 4’s Tom Kierein had this graphic this A.M.:
— Tom Kierein (@TomKierein) January 27, 2015