Every year, Washintong D.C. celebrates the beginning of spring with the National Cherry Blossom Festival. Visitors can walk the national mall and tidal basin to bask in the beauty of countless budding cherry blossom trees. The event (like all in DC) is free to the public and culminates with cherry blossom parade near the peak of the blooms.
The cherry blossom’s begin to bud in mid/late march and peak in early’ish April. Crowds are numerous and parking is a hassle (like always). Take the DC Metro if possible.