National Cherry Blossom Festival

This is by far the most famous of Washington's annual festivals.  When the thousands  of cherry blossom trees bloom every spring, it's time to celebrate.  The two week long festival takes place mostly on the mall and around the Jefferson Memorial, where most of the trees are planted.  Events vary by year, but always include the Cherry Blossom Parade, Japanese heritage events, and a thriving street festival.

The date for this festival vary by year depending on when the trees are in bloom, so check their website beforehand.  Most events are free, but the parade does require tickets.