$449 Cheap Flights from Tri-Cities (TRI) to Sidney (SDY)

View $449 flight on Tue, Dec 30, 2025Opens in a new window

Popular airlines from Tri-Cities, TN (TRI-Tri-Cities Regional) to Sidney, MT (SDY-Sidney-Richland Municipal)

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Cheap Flights from Tri-Cities to Sidney (TRI-SDY)

Prices were available within the past 7 days and start at $449 for one-way flights and for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frequently asked questions

How much does a flight from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY) cost?
Secure a cheap one-way flight from $449 or cheap return flight from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY)?
is the cheapest month to fly from TRI to SDY. Traveling outside of peak seasons is often the key to scoring lower fares.
What is the cheapest airline that flies from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY)?
Use the filters on Expedia to compare different airlines and find the most affordable carrier that'll take you from TRI to SDY. Then, sort your results by "Price (lowest to highest)" to snag the best deal available.
How many flights per day from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY)?
There aren't any daily direct flights from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY). But you can book flights with layovers. Filter your search results on Expedia to include one or two stops, and you'll be on your way before you know it.
What day of the week has the most flights from TRI to SDY?
Typically you'll find the greatest selection of flight options on a Friday. Tuesdays are often the quietest.* But this can vary depending on the time of year, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY)?
To avoid potential delays on the Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY) route, travel before 3 PM. Departures after this hour have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY) last-minute?
Last-minute bookings from TRI to SDY are typically more expensive. To secure the best prices, start looking for flights as early as possible. That being said, if you can play around with your travel dates, you may land a cheap fare right before you leave.
Is it cheaper to book a TRI to SDY flight and hotel package?
Booking a TRI to SDY flight and hotel package tends to be cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your trip all in one place. Pick from our impressive range of accommodations and then add car rentals, flights and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Tri-Cities Regional Airport (TRI) to Sidney-Richland Municipal Airport (SDY)?
If you booked your TRI to SDY flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of fare you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more information.

Travel information

Origin airport
Tri-Cities Regional
Destination airport
Sidney-Richland Municipal
Distance
1351 mi

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Tri-Cities to Sidney Flights

The cheapest times to fly from Tri-Cities to Sidney

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Tri-Cities to Sidney are during the month of . You can find some of the cheapest flights from Tri-Cities to Sidney with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Tri-Cities to Sidney

Sunday is one of the best days to book for cheap flights from Tri-Cities to Sidney: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Tri-Cities to Sidney

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Tri-Cities to Sidney in 2026. You can also book with separate airlines for your outbound and return journeys, from $449 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Tri-Cities to Sidney flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Tri-Cities to Sidney airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Tri-Cities to Sidney Flights

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