Washington, DC is hot and humid in the summers, but the rest of the year is fairly mild by comparison -- cold but with little snow in the winters, falls and springs that are gentle transitions.

When to Go

The best times to come are also the most popular of course, as DC is one of the most-visited tourist destinations in the world. For instance, book your hotels long in advance during The National Cherry Blossom Festival, usually in early April. During presidential inaugurations, every 4 years, the city is packed for days. Not to mention during other political events, from protests to major Supreme Court cases, which all bring visitors.  The streets of  are packed with tourists in the summer.  June and July tend to be the busiest months for tourists, with numbers starting to dwindle with the DC August heat and humidity.  Also, if you are planning a summer visit, keep in mind that Congress recesses for the entire month of August, so you will not be able to see your government in action.  This does however, lead to shorter waits at restaurants and a few more available hotel rooms.  Late Spring and early Fall are ideal times to visit.  The weather can be perfect at the end of April/beginning of May and at the beginning of October.  These can also be very busy times with school groups visiting.  Winter brings blustery temperatures, but also shorter lines at museums and restaurants. Just note that on windy winter days, the gusts at attractions which are on hills (like the Washington Monument) can be downright gale-force -- plan accordingly. 

Washington DC - Weather Info