Miami to Washington, DC

Between Miami and Washington, DC, 3.5 million passengers flew nonstop in 2025, on 26 thousand flights of about 921 miles and 2.1 hours in the air. The average passenger accounted for about 144 kg of CO2 from the fuel burned, from 112 kg on Spirit Airlines to 190 kg on Delta Air Lines.

144 kgCO2 per passenger, average
921 milesabout 2.1 hours in the air
3.5 millionpassengers in 2025
79%of seats filled

CO2 per passenger, airline by airline

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

Miami to Washington, DC by airline, 2025

Airline	Share of passengers	Flights (thousands)	Main aircraft	Seats per flight	Seats filled	kg CO2 per passenger
American Airlines	37%	9.3	Boeing 737-800, Boeing 737 MAX 8	167	82%	147
Southwest Airlines	26%	7.5	Boeing 737-700, Boeing 737 MAX 8	161	74%	149
Spirit Airlines	11%	2.3	Airbus A321neo, Airbus A320-200	199	82%	112
United Airlines	10%	2.5	Boeing 737-800, Boeing 737 MAX 9	173	84%	133
JetBlue	9%	2.7	Airbus A220-300, Airbus A320-200	151	80%	164
Frontier Airlines	4%	0.9	Airbus A320neo, Airbus A321neo	207	73%	122
Delta Air Lines	2%	0.7	Airbus A319, Airbus A321	133	79%	190

What explains the differences

It's number 20 of the 100 busiest city pairs by passengers, and number 54 for the lowest CO2 per mile flown (0.16 kg per passenger-mile, number 1 being the lowest). A typical route of 921 miles in this set comes out at about 142 kg, so this one is close to that.

The flights use more than one pair of airports: DCA to MIA (31%), BWI to FLL (25%), BWI to MIA (18%). The figures here cover all of them.

The airlines on this route differ by 70% per passenger. Spirit Airlines burned 1,882 gallons per flight and 164 passengers on each, and Delta Air Lines 2,049 gallons and 105 passengers. Fuel burned per flight explains about 16% of the gap and the number of passengers on each flight the other 84%. Spirit Airlines flew 82% full here against 79% for Delta Air Lines, flying mostly Airbus A321neo against Airbus A319.

For comparison, the EPA default factor for a flight of this length (0.129 kg per passenger-mile) would give 119 kg. The EPA figure is a national average for flights of that length. The measured figure for this route is 22% higher.

2019 compared with 2025

In 2019 the route carried 3.1 million passengers on 23 thousand flights. In 2025 it carried 3.5 million, up 13%, on 26 thousand flights, up 13%. The average flight had 153 seats then and 166 now, and 87% of them were filled against 79%.

CO2 per passenger was 146 kg in 2019 and 144 kg in 2025, down 0.7%. Fuel burned per flight was down 1.2% (1,974 gallons to 1,951) and passengers per flight were down 0.4% (132 to 132). The distance flown was about the same (917 miles then, 921 now).

American Airlines led in both years, with 36% of passengers in 2019 and 37% in 2025. Southwest Airlines lost the most, 31% to 26%. Frontier Airlines and Delta Air Lines didn't have 1% of the passengers in 2019 and now together carry 6%.

Airline by airline, JetBlue went from 189 kg to 164 kg per passenger (101 seats per flight to 151, main aircraft Airbus A320-200 then and Airbus A220-300 now); Southwest Airlines went from 143 kg to 149 kg per passenger (152 seats per flight to 161, main aircraft Boeing 737-700 in both years).

Miami to Washington, DC, 2019 and 2025

Measure	2019	2025
Passengers (thousands)	3,076	3,473
Flights (thousands)	23.3	26.4
Seats filled	87%	79%
Gallons of fuel per flight	1,974	1,951
kg CO2 per passenger	146	144

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.

Miami to Washington, DC and back: time in the air

Flights from Washington, DC to Miami spent 133 minutes in the air on average in 2025, against 125 minutes from Miami to Washington, DC: 7 minutes longer, 6% more. The route runs mostly north to south, so the winds on the day, routing and congestion decide the difference.

At this route's average burn of about 908 gallons per flight hour, those extra minutes cost about 109 gallons per flight, which is about 0.8 gallons or 8 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
Washington, DC to Miami	132.5	13,185
Miami to Washington, DC	125.3	13,189

Fly or drive

Driving is about 1,078 miles by road, which we estimate as 1.17 times the straight-line distance. An average car emits about 320 kg of CO2 on the trip, at the EPA figure of 0.297 kg per vehicle-mile. Alone, that's 122% more than the 144 kg for a passenger on the flight.

With 3 people in the car, driving comes out lower per person than the flight (107 kg each, and 80 kg each for four). A larger SUV or pickup (0.394 kg per mile) would emit about 425 kg per vehicle.

CO2 per person, Miami to Washington, DC. 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: Ronald Reagan Washington National Airport, Miami International Airport, Baltimore/Washington International Thurgood Marshall Airport, Fort Lauderdale-Hollywood, Washington Dulles 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.