In terms of precipitation, rainfall in Sidney, Montana ranges from 0.0 - 2.8 inches per month. June is typically the wettest month, when rainfall can reach 2.8 in. January is typically the driest time to visit Sidney, Montana when rainfall is around 0.0 in.

If weather is an important factor for your trip to Sidney, Montana, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 10.4 F).

What is the cheapest time of day to fly from IAD to SDY?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Washington, D.C. Dulles Intl Airport to Sidney, Montana as you normally would.

Most accurate provider : When it comes to deals on Washington, D.C. Dulles Intl Airport-Sidney, Montana flights, users find the pricing of Expedia to be most consistent on Cheapflights vs. Expedia Users can find the same prices on Washington, D.C. Dulles Intl Airport-Sidney, Montana flight deals on Cheapflights vs. Expedia 90-95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Sidney, Montana flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Washington, D.C. Dulles Intl Airport-Sidney, Montana flights, Cheapflights users trust Expedia the most. Expedia has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Sidney, Montana flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

What airport do you fly into for flights to Sidney from Washington, D.C. Dulles Intl?

For a flight from Washington, D.C. Dulles Intl to Sidney, you will be flying into Richland Municipal. Sidney Richland Municipal (SDY) is just 1.8 mi from the center of the city. Richland Municipal is the only Sidney airport and it handles 0 inbound flights from Washington, D.C. Dulles Intl per day. 0 airlines have flights to Sidney Richland Municipal from Washington, D.C. Dulles Intl on a regular basis.

Can I find deals for flights from Dulles Intl to Sidney that include hotel bookings?

Yes. In addition to deals on Dulles Intl to Sidney flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Dulles Intl to Sidney?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Sidney.

Can I find deals for business class flights from Dulles Intl to Sidney?

Yes. Cheapflights offers flight deals from Dulles Intl to Sidney by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$655+ Flights from Washington, D.C. Dulles Intl Airport to Sidney, MT

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

Find cheap flights from Dulles Intl to Sidney with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Dulles Intl to Sidney

Most accurate provider	Expedia 2 stars
Most trusted provider	Expedia 3 stars
Round-trip from	$655 (United)

Provider with most accurate pricing for Washington, D.C. Dulles Intl-Sidney Richland Municipal flight deals.

Search Deals

Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Sidney Richland Municipal flights.

Search Deals

From Washington, D.C. Dulles Intl to Sidney Richland Municipal

Search Deals

Find flight deals from Dulles Intl to Sidney

Cheapest flights from Dulles Intl to Sidney
Explore the most affordable flight options available from Dulles Intl to Sidney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 7, 2025.

Wed 12/312:45 pmIAD - SDY

2 stops27h 32mMultiple Airlines

Wed 12/109:45 amSDY - IAD

2 stops11h 30mMultiple Airlines

Deal found 11/5

$655

Best flights from Dulles Intl to Sidney
Discover carefully curated flight deals from Dulles Intl to Sidney that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated November 7, 2025.

Wed 12/312:45 pmIAD - SDY

2 stops27h 32mMultiple Airlines

Wed 12/109:45 amSDY - IAD

2 stops11h 30mMultiple Airlines

Deal found 11/5

$655

Last-minute flights from Dulles Intl to Sidney
Discover last-minute flight deals from Dulles Intl to Sidney. Data last updated November 7, 2025 and is based on user searches.

Wed 12/312:45 pmIAD - SDY

2 stops27h 32mMultiple Airlines

Wed 12/109:45 amSDY - IAD

2 stops11h 30mMultiple Airlines

Deal found 11/5

$655

Cheapflights Fare Finder

Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Sidney that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Washington, D.C.Sidney

IAD - SDY

IADSDY

Washington, D.C. Dulles Intl

Wed 12/3

12:45 pm-2:17 pm

2 stops27h 32m

Sidney Richland Municipal

Wed 12/10

9:45 am-11:15 pm

2 stops11h 30m

$655

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/5

Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Sidney, Montana flights, users find the pricing of Expedia to be most consistent on Cheapflights vs. Expedia Users can find the same prices on Washington, D.C. Dulles Intl Airport-Sidney, Montana flight deals on Cheapflights vs. Expedia 90-95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Sidney, Montana flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Sidney, Montana flights, Cheapflights users trust Expedia the most. Expedia has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Sidney, Montana flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Dulles Intl to Sidney

Have a flexible travel schedule? Discover the best time to fly to Sidney from Dulles Intl with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Related info for your journey

What airport do you fly into for flights to Sidney from Washington, D.C. Dulles Intl?
For a flight from Washington, D.C. Dulles Intl to Sidney, you will be flying into Richland Municipal. Sidney Richland Municipal (SDY) is just 1.8 mi from the center of the city. Richland Municipal is the only Sidney airport and it handles 0 inbound flights from Washington, D.C. Dulles Intl per day. 0 airlines have flights to Sidney Richland Municipal from Washington, D.C. Dulles Intl on a regular basis.
Can I find deals for flights from Dulles Intl to Sidney that include hotel bookings?
Yes. In addition to deals on Dulles Intl to Sidney flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Dulles Intl to Sidney?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Sidney.
Can I find deals for business class flights from Dulles Intl to Sidney?
Yes. Cheapflights offers flight deals from Dulles Intl to Sidney by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Dulles Intl to Sidney

Dulles Intl to Bozeman flights

Baltimore to Bozeman flights

Reagan-National to Bozeman flights

Baltimore to Kalispell flights

Reagan-National to Kalispell flights

Dulles Intl to Kalispell flights

Dulles Intl to Great Falls flights

Baltimore to Great Falls flights

Reagan-National to Great Falls flights

Baltimore to Missoula flights

Dulles Intl to Billings flights

Dulles Intl to Missoula flights

Baltimore to Billings flights

Reagan-National to Missoula flights

Baltimore to Cody flights

Reagan-National to Billings flights

Dulles Intl to Helena flights

Baltimore to Helena flights

Reagan-National to Helena flights

Dulles Intl to Cody flights

Reagan-National to Cody flights

Dulles Intl to Butte flights

Baltimore to Butte flights

Reagan-National to Butte flights

Baltimore to West Yellowstone flights

Dulles Intl to West Yellowstone flights

Reagan-National to West Yellowstone flights

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

$655+ Cheap flights from Dulles Intl (IAD) to Sidney, MT (SDY)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/3. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Dulles Intl to Sidney with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Dulles Intl to Sidney

Most accurate provider

Most trusted provider

Round-trip from

Find flight deals from Dulles Intl to Sidney

Cheapest flights from Dulles Intl to SidneyExplore the most affordable flight options available from Dulles Intl to Sidney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 7, 2025.

Explore the most affordable flight options available from Dulles Intl to Sidney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 7, 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Sidney that are best for you.

Best time to book a flight from Dulles Intl to Sidney

Have a flexible travel schedule? Discover the best time to fly to Sidney from Dulles Intl with our price prediction graph.

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl to Sidney. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

What airport do you fly into for flights to Sidney from Washington, D.C. Dulles Intl?

Can I find deals for flights from Dulles Intl to Sidney that include hotel bookings?

How can I find direct flights from Dulles Intl to Sidney?

Can I find deals for business class flights from Dulles Intl to Sidney?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Dulles Intl to Sidney

See prices for flight routes from nearby airports that may be better suited for you.

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from Dulles Intl to Sidney
Explore the most affordable flight options available from Dulles Intl to Sidney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 7, 2025.