Netflights is free and simple to use. You can view all 33 of the weekly flights to Washington DC, flown by six airlines. Having them all in one place makes it easy to compare prices and find the best deal for you.
Washington DC actually has two airports.
Searching by month is the best way to get a feel for the overall cost of flights throughout the year.
On average, the 5441 km flight from Belfast to Washington DC takes 15 hrs 25 mins. If you're landing late, why not take a look at hotels near the airport? We've got a range of accommodation and car hire options across USA.