The point of the articles below is that it can still snow into April, not that it will. Pattern last week of March will have to be monitored.
Source: Washington Post
From the start of snow records in the late 1880s, fairly regular April snow events continued until 1924. During that period, 2 storms were particularly noteworthy: (1) the April 3, 1915 Easter weekend storm, which left 3.5 inches in D.C., but 15-20 inches in a swath from Philadelphia to Dover, DE; and (2) the April Fool’s Storm of April 1, 1924, which dumped 5-6 inches of snow on the Nation’s Capital and 9 inches in Baltimore. The latter was D.C.’s greatest official April snowstorm and appeared to be the culmination of regular April snow events in Washington. Since then, there’s been only about one per decade.
Also of note: On March 29, 1942 11.5 inches was measured at Reagan National. The storm produced over 2 feet of snow in parts of Maryland and northwestern Virginia. That snowstorm also ranks as Baltimore’s seventh-largest storm on record; 22 inches was measured.