The cheapest times to fly from SDY to IAD are

  • January 1st to March 11th
  • April 9th to May 13th
  • October 15th to March 11th (except the weeks of November 26th, December 10th, December 17th, and December 24th)

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from SDY to IAD is late October. Prices can be as high as $1014 for Sunday flights during late July, or as low as $514 for Tuesday flights around late October.


When to Fly to Washington

Flying from Sidney, MT (SDY) to Washington, DC (IAD) will usually cost between $564 to $903 per person if booking more than four weeks in advance. On average the very cheapest time to fly is late October with an average ticket price of $587. Due to high demand the most expensive time to fly is late July, with an average price of $855. Planning your trip to low-cost times can easily save you $268 on economy flights and even more on first-class flights. Generally, any price below $742 can be considered a good price for a round-trip SDY to IAD flight.

See below for a graph of average weekly prices for the SDY to IAD route. All prices are for round-trip tickets in USD.

SDY to IAD Flight Prices

Compared to other flights, the SDY to IAD flight is cheaper than the average and costs much less than the average flight leaving from Sidney. The average price per mile (for a direct flight) is $0.31, which is in the normal range for a flight.


Flight Prices by Day of the Week

Tuesday is usually the cheapest day to fly to IAD, and Wednesday the cheapest day to fly back into SDY. Sundays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $79 (10%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Tuesday and returning a week later will cost an average of $717. Return trip prices are from the IAD to SDY flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from SDY to IAD can generally find a 2-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 3 hour 37 minutes may not be realistic.


Flight Hacking SDY to IAD

Flight hacking is when you book two tickets instead of a layover, sometimes with different airlines. You will need to either bring only a carry-on bag (highly recommended) or leave yourself plenty of time to go through security again. Flight hacking is completely allowed, but airlines don’t always tell you the cheapest way to get from SDY to IAD — but Champion Traveler does!

Hack #1: Billings, MT (SDY > BIL > IAD)

  • Price for both tickets: $513
  • Average savings: $229 (30.86%)

See SDY to BIL flights


Flight Questions Answered

Still have questions about flying from SDY to IAD? We’ve got answers.

Which airlines fly this route?

You can find 6 major airlines flying this route most often: Alaska, American, Cape Air, Delta, Frontier, United, and potentially more during busy seasons.

How far away is it from Washington Dulles International Airport to Sidney Richland Regional Airport?

The distance between the two airports is roughly 1464 miles or 2356 kilometers.

How long does it take to fly from SDY to IAD?

The real-world flight time for a nonstop SDY to IAD flight is about 3 hour 37 minutes.

How many flights go between Sidney, MT and Washington, DC?

It depends on the day of the week and the date, but a typical day might have around 15 available flights from SDY to IAD.


Airport Location Info


Departing Airport

Origination codeSDY
Origination airport nameSidney Richland Regional Airport
CitySidney, MT
Countrythe United States

Return Airport

Destination codeIAD
Destination airport nameWashington Dulles International Airport
CityWashington, DC
Countrythe United States


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.