There was an event in March '95. It was 70s early in the day, and we ended up with 2-3 inches of snow that evening. Only time I've ever mowed the lawn in shorts and a tshirt and shoveled snow on the same day.
Edit: Looks like it was March 8, 1995. Highs were in the mid-60s, not 70s. IAD had 1.8", DC .4", and BWI .2"