What do I wear on my trip to Washington D.C.?

I suggest wearing layers. This way you can take some off if you don't need them all. As far as snow, there is a low pressure system coming up through wednesday afternoon into Thursday morning. However, it is going to be mostly rain with a little wintery mix. Therefore, bring an umbrella if you will be there then. If you are going to be walking around a lot, this will help to warm you up at least a little! If not, they tend to keep the temp indoors at a reasonable number. Hope you have a great trip! Enjoy yourself! :) P.S- rain boots are fashionable and perfect for the occasion! :) have a great time!