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The cheapest month and booking window for 34 routes from PHX, plus Sky Harbor parking hacks. We'll also email you the best fares from Phoenix every week.
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The cheapest month and best time to book for 34 routes from PHX, plus the best verified fares in your inbox every week.
Phoenix Sky Harbor (PHX) has six low-cost airlines: Southwest, Frontier, Allegiant, Breeze, Sun Country and Volaris. Southwest is the big one. It flies nonstop on 22 of the 37 popular routes we track from PHX, and Frontier on 16. Allegiant flies mostly from Phoenix-Mesa Gateway (AZA), the Valley's second airport. Spirit Airlines left Phoenix on January 8, 2026.
| Airline | Terminal | Nonstops on our tracked routes |
|---|---|---|
| Southwest | Terminal 4 | 22 routes, including Las Vegas, Chicago, Denver, Seattle, Dallas, San Diego, Los Angeles, San Francisco |
| Frontier | Terminal 3 | 16 routes, including Las Vegas, Chicago, Denver, Seattle, Dallas, San Diego, Los Angeles, San Francisco |
| Volaris | Terminal 4 | Mexico: Guadalajara, Culiacán |
| Allegiant | Terminal 3 (most flights leave from Mesa Gateway) | Mostly smaller cities in the Midwest and Mountain West |
| Breeze | Terminal 3 | A small, changing set of routes. Check breezeairways.com |
| Sun Country | Terminal 3 (also Mesa Gateway in winter) | Mainly Minneapolis-St. Paul |
"Tracked routes" are the 37 popular destinations on our Phoenix route pages, not every city each airline serves. Terminals 3 and 4 are separate buildings, so check yours before you leave home (our PHX airport guide lists every airline).
Southwest is one of the two largest airlines at Sky Harbor, alongside American. It is the only nonstop to Love Field in Dallas, Houston Hobby, Long Beach and Oakland from Phoenix, and it competes on most West Coast, Mexico and Hawaii routes. Two things changed recently: since May 2025 Southwest charges for checked bags on most fares, and since January 2026 it assigns seats instead of open seating. Compare it with the others on the full price, bags included.
Frontier flies from Terminal 3 to 16 of our tracked routes, from short hops like Las Vegas, San Diego and Denver to Atlanta, Orlando and Los Cabos. Its base fares are often the lowest on the search page, but a full-size carry-on, a checked bag and a seat assignment all cost extra on the basic fare.
Allegiant carries about 98% of the passengers at Phoenix-Mesa Gateway (AZA) and flies from there to around 40 cities, many of them smaller airports such as Provo, Fargo, Sioux Falls and Bozeman. Some have no nonstop from Sky Harbor at all, so check both airports. Sun Country adds a seasonal Minneapolis flight from Mesa between November and April. If you live in the East Valley, Mesa Gateway can also be the closer airport. See Sky Harbor vs Mesa Gateway.
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Southwest, Frontier, Allegiant, Breeze, Sun Country and Volaris fly from Phoenix Sky Harbor. Allegiant flies mostly from Phoenix-Mesa Gateway (AZA), where Sun Country also has a seasonal Minneapolis flight.
Terminal 3. Allegiant, Breeze and Sun Country are also in Terminal 3. Southwest and Volaris are in Terminal 4.
No. Spirit ended its Phoenix Sky Harbor service on January 8, 2026. It had been flying nonstop to Detroit and Fort Lauderdale.
It depends on the route. Southwest and Frontier cover the most routes with low fares (22 and 16 of the 37 routes we track), but American, Delta and United often match them. Compare the total with bags, and compare nearby airports: to Dallas, DFW has been far cheaper than Love Field.
Mostly from Phoenix-Mesa Gateway (AZA) in southeast Mesa, to around 40 cities, many of them smaller airports in the Midwest and Mountain West.
Sources: skyharbor.com airlines by terminal (October 2026); FOX 10 Phoenix on Spirit leaving PHX (November 2025); Mesa Gateway passenger statistics and FlightConnections AZA route list (2026); KAYAK route data for the fares (past 12 months, checked October 2026). Route counts come from the routes on our site.
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The cheapest month and booking window for 34 routes from PHX, plus Sky Harbor parking hacks. We'll also email you the best fares from Phoenix every week.