The most practical way to reach Washington, D.C. from Sioux Falls is by air. You will fly from Sioux Falls Regional Airport (FSD) to Reagan National (DCA) or Dulles (IAD), typically with one connection. The total travel time is around 5-6 hours. Driving is not recommended due to the 1,300-mile distance.
Total Distance: 2,100 km driving, 1,800 km air distance.
Reagan National (DCA) is much closer to the city center.
Spring for the Cherry Blossom Festival or autumn for mild weather.