Distance between cities › USA › South Dakota › Dewey, SD › Distance from Dewey to Seattle–Tacoma International Airport Book Hotels

Distance from Dewey, SD to SEA Airport

Distance

1,161 mi

Time

20 hours 42 mins

Gas Cost

$108 - $210

Helpful Inaccurate

There are 922.84 miles from Dewey to Seattle–Tacoma International Airport (SEA) in northwest direction and 1,161 miles (1,868.45 kilometers) by car, following the I-90 route.

Dewey and SEA Airport are 20 hours 42 mins far apart, if you drive non-stop .

This is the fastest route from Dewey, SD to SEA Airport. The halfway point is Warm Springs, MT.

Please note the time difference between Dewey, SD and SEA Airport is 1 hour. The current time in Dewey is 12:22 am (Mar 12) and the current time in SEA Airport is 11:22 pm (Mar 11).

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Lowest Price Rental Cars in Dewey, SD

Planning on renting a car to go from Dewey, SD to SEA Airport? Here there are some offers to rent a car in Dewey, SD

Small

From $14

Intermediate

From $18

Full-size

From $24

SUVs

From $28

Vans

From $40

Compare rental car prices in Dewey »

Gas Consumption and Emissions

A car with a fuel efficiency of MPG will need 46.63 gallons of gas to cover the route between Dewey, SD and SEA Airport.

The estimated cost of gas to go from Dewey to SEA Airport is $152.09.

During the route, an average car will release 913.48 pounds of CO₂ to the atmosphere. The carbon footprint would be 0.79 pounds of CO₂ per mile.

Average USA gas price used for calculation is $3.26 per gallon of regular gas. Price last updated on March 12, 2026.
Read more about our CO₂ calculation.

Halfway Point Between Dewey, SD and SEA Airport

If you want to meet halfway between Dewey, SD and SEA Airport or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 46.136749 and -112.775200, or 46º 8' 12.2964" N, 112º 46' 30.72" W. This location is 580.48 miles away from Dewey, SD and SEA Airport and it would take approximately 10 hours 21 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is Warm Springs, MT, situated 614 miles from Dewey, SD and 577 miles from SEA Airport. It would take 9 hours 21 mins to go from Dewey to Warm Springs and 8 hours 24 mins to go from SEA to Warm Springs.