Washington DC is indeed a year-round destination. The best time to visit Washington DC would be in the fall season, from September to November. The weather conditions are pleasant with lesser tourists. Regardless of the time of your visit, the memorials remain open 24x7, and the Smithsonian museums operate on all days except Christmas. Overall, the weather is relatively mild and the city witnesses four distinct seasons, of almost the same length. Expect cold and snowy winters, scorching and humid summers and rainstorms in extremely short bursts. One of the most beautiful things that Washington DC has to offer is its beloved cherry blossoms. If you want to witness the cherry blossom trees at its best, then it is recommended to plan a trip between mid-March and June. For tourists who are looking to partake in spectacular public celebrations, the best time to visit would be during the 4th of July celebrations.