Rankings / States / California
California airports and their flight routes
This page puts the 7 California airports this site tracks side by side: LAX, SNA, SFO, OAK, ONT, SJC and BUR. Counting an airport on a route when it carries at least 5% of the route's passengers, together they cover 26 of the busiest US routes in 2025, 10 more than LAX alone.
The airports
An airport counts on a route when it carries at least 5% of the route's passengers, the same rule as the airport pages. Smaller shares aren't counted, so an airport can have a few passengers on a route without it appearing here. "Routes" is how many of the tracked routes each airport counts on. "Only here" is how many of those have no other airport on this page at 5% or more. This covers the California airports with their own airport page, not every airport in the state.
Where the airports overlap
22 of the 26 routes have more than one of these airports with at least 5% of their passengers, and 4 have just one. On Los Angeles to San Francisco, 6 of them clear that share: BUR, LAX, OAK, SFO, SJC and SNA.
- LAX is the only airport here with at least 5% of 3 routes, including Los Angeles to Honolulu and Los Angeles to Washington, DC.
- SFO is the only airport here with at least 5% of one route: New York to San Francisco.
Flight CO2 across these routes
The lowest-CO2 route here is Los Angeles to Las Vegas, at 53 kg per passenger over 227 miles. The highest is New York to San Francisco, at 414 kg over 2,578 miles. Longer trips burn more fuel, so this range shows how far people fly, not which airport is cleaner.
Every route in one table, 2025
Busiest first. Each route appears once, with the airports on this page that carry at least 5% of its passengers. CO2 is per passenger, one way, for the whole route across all its airports.
How these routes have changed
26 of these routes also have an earlier year on file. The biggest changes are below, each against that route's own earlier year. They describe the whole route, not one airport.
- Dallas-Fort Worth to San Francisco: 227 kg per passenger in 2019, 193 kg in 2025 (15% lower), on a route of the same length, 1,458 miles.
- Los Angeles to Sacramento: 83 kg per passenger in 2019, 92 kg in 2025 (11% higher), on a route of the same length, 379 miles.
- San Francisco to Phoenix: 119 kg per passenger in 2019, 107 kg in 2025 (10% lower), on a route of the same length, 641 miles.
Sources and limits
Source: US Bureau of Transportation Statistics (BTS), T-100 traffic and Schedule T-2 fuel filings; US EPA jet-fuel CO2 factor. See the route calculation method, route dataset and airport dataset.
Which state an airport is in comes from Wikidata, traced from each airport's location up to the state, retrieved 2026-11-06. Each step below links to the saved Wikidata record.
- LAX: Los Angeles International Airport > Los Angeles > Los Angeles County > California.
- SNA: John Wayne Airport > Orange County > California.
- SFO: San Francisco International Airport > San Mateo County > California.
- OAK: Oakland San Francisco Bay Airport > Oakland > Alameda County > California.
- ONT: Ontario International Airport > California.
- SJC: San Jose International Airport > San Jose > Santa Clara County > California.
- BUR: Hollywood Burbank Airport > California.
The airline filings don't split fuel by airport. The CO2 figures cover every airport on a city pair, so they can't show how switching airports changes emissions. Selected and rounded airport shares aren't added into state passenger or emissions totals. Fuel burned only is counted, without non-CO2 warming effects.
Compare another state: Florida, Texas. Return to the state index.