Dallas-Fort Worth to Seattle

Between Dallas-Fort Worth and Seattle, 1.7 million passengers flew nonstop in 2025, on 11 thousand flights of about 1,660 miles and 3.5 hours in the air. The average passenger accounted for about 211 kg of CO2 from the fuel burned, from 193 kg on Southwest Airlines to 251 kg on Delta Air Lines.

211 kgCO2 per passenger, average
1,660 milesabout 3.5 hours in the air
1.7 millionpassengers in 2025
89%of seats filled

CO2 per passenger, airline by airline

Kilograms of CO2 per passenger, one way, 2025. Fuel burned only. Less is better.

Dallas-Fort Worth to Seattle by airline, 2025

Airline	Share of passengers	Flights (thousands)	Main aircraft	Seats per flight	Seats filled	kg CO2 per passenger
American Airlines	55%	5.4	Airbus A321, Airbus A321neo	191	90%	216
Alaska Airlines	34%	3.7	Boeing 737-900ER, Boeing 737 MAX 9	175	89%	197
Delta Air Lines	8%	1.4	Airbus A220-300	111	86%	251
Southwest Airlines	2%	0.3	Boeing 737 MAX 8, Boeing 737-700	165	93%	193

What explains the differences

It's number 91 of the 100 busiest city pairs by passengers, and number 8 for the lowest CO2 per mile flown (0.13 kg per passenger-mile, number 1 being the lowest). A typical route of 1,660 miles in this set comes out at about 233 kg, so this one is 9.2% below it.

The flights use more than one pair of airports: DFW to SEA (96%), DAL to SEA (4%), AFW to SEA (0%). The figures here cover all of them.

The airlines on this route differ by 30% per passenger. Southwest Airlines burned 3,033 gallons per flight and 153 passengers on each, and Delta Air Lines 2,454 gallons and 95 passengers. The gap comes from how many passengers share each flight, not from fuel burned per flight. Southwest Airlines flew 93% full here against 86% for Delta Air Lines, flying mostly Boeing 737 MAX 8 against Airbus A220-300.

For comparison, the EPA default factor for a flight of this length (0.129 kg per passenger-mile) would give 214 kg. The EPA figure is a national average for flights of that length. The measured figure for this route is 1.3% lower.

2019 compared with 2025

In 2019 the route carried 1.5 million passengers on 11 thousand flights. In 2025 it carried 1.7 million, up 12%, on 11 thousand flights, up 3%. The average flight had 159 seats then and 175 now, and 90% of them were filled against 89%.

CO2 per passenger was 228 kg in 2019 and 211 kg in 2025, down 7.4%. Fuel burned per flight was up 0.9% (3,342 gallons to 3,371) and passengers per flight were up 9.0% (143 to 156). The distance flown was about the same (1,662 miles then, 1,660 now).

American Airlines led in both years, with 57% of passengers in 2019 and 55% in 2025. Alaska Airlines gained the most share, 26% to 34%. Southwest Airlines lost the most, 7% to 2%. Delta Air Lines didn't have 1% of the passengers in 2019 and now carries 8%. Horizon Air and Spirit Airlines and SkyWest Airlines no longer reach 1% of passengers, having had 11% in 2019.

Airline by airline, American Airlines went from 230 kg to 216 kg per passenger (174 seats per flight to 191, main aircraft Airbus A321 in both years); Alaska Airlines went from 203 kg to 197 kg per passenger (175 seats per flight to 175, main aircraft Boeing 737-900ER in both years).

The airports changed too: DFW to SEA handled 84% of the passengers in 2019 and 96% in 2025.

Dallas-Fort Worth to Seattle, 2019 and 2025

Measure	2019	2025
Passengers (thousands)	1,507	1,684
Flights (thousands)	10.6	10.8
Seats filled	90%	89%
Gallons of fuel per flight	3,342	3,371
kg CO2 per passenger	228	211

Kilograms of CO2 per passenger on the airlines that flew the route in both years. 2019 figures use that year's filings and estimated aircraft fuel rates, with type-average replacements for missing or outlying filings as described in the methodology. Less is better.

Dallas-Fort Worth to Seattle and back: time in the air

Flights from Dallas-Fort Worth to Seattle spent 226 minutes in the air on average in 2025, against 199 minutes from Seattle to Dallas-Fort Worth: 27 minutes longer, 14% more. That's the westbound direction, into the prevailing west-to-east winds, which at flight levels often blow at well over 50 miles an hour.

At this route's average burn of about 952 gallons per flight hour, those extra minutes cost about 427 gallons per flight, which is about 2.7 gallons or 27 kg of CO2 for each passenger on the slower direction. The route figure above averages both directions.

Time in the air by direction, 2025

Direction	Average minutes in the air	Flights
Dallas-Fort Worth to Seattle	225.9	5,425
Seattle to Dallas-Fort Worth	199.0	5,399

Fly or drive

Driving is about 1,942 miles by road, which we estimate as 1.17 times the straight-line distance. An average car emits about 577 kg of CO2 on the trip, at the EPA figure of 0.297 kg per vehicle-mile. Alone, that's 173% more than the 211 kg for a passenger on the flight.

With 3 people in the car, driving comes out lower per person than the flight (192 kg each, and 144 kg each for four). A larger SUV or pickup (0.394 kg per mile) would emit about 765 kg per vehicle.

CO2 per person, Dallas-Fort Worth to Seattle. Driving figures divide one car's emissions between the people in it. See flying vs driving for other trip lengths.

Flights are listed under the airline that operates them, so regional flying appears under the regional. How the CO2 and drive figures are worked out is in the methodology.

Routes with shared cities or nearby CO2 per mile

Airports on this route: Dallas/Fort Worth International Airport, Seattle-Tacoma International Airport.

Airport and airline references

Source: US Bureau of Transportation Statistics (BTS), T-100 traffic and Schedule T-2 fuel filings; US EPA transport emission factors. See the methodology.

See all routes, or how the airlines compare overall on the airline pages.