Carrier route record
WNATL→PHX
Southwest Airlines · Atlanta to Phoenix
- Flights
- 633
- Period
- July 2025 to June 2026
- Share of route
- 17%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on ATL to PHX sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 633 flights. The strongest carrier on the route with a full sample, American Airlines, flew 614 at 79.2% on time.
The national on-time rate over the same period is 77.6%, so Southwest on ATL to PHX runs 6 points behind the country as a whole. Across a thousand flights that is about 56 extra late arrivals.
Key figures
On time
72.0%
Arrivals under 15 minutes late, of 629 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.32%
National rate is 1.81%
Whole route
75.4%
Every carrier on ATL to PHX, 3,762 flights
These figures cover 633 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Southwest against every carrier on ATL to PHX
Southwest flew 633 of the 3,762 flights on ATL to PHX, about 17% of it. Its 72.0% on time is 3 points worse than the route as a whole, which runs 75.4%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from American at 79.2% to Frontier at 67.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 614 | 79.2% | 94 min | 0.49% | B+ |
| Delta Air Lines | 2,301 | 76.0% | 59 min | 0.87% | B+ |
| Southwest Airlines (this page) | 633 | 72.0% | 48 min | 0.32% | C+ |
| Frontier Airlinesthin sample | 214 | 67.8% | 74 min | 0.93% | C+ |
No carrier stands out. American tops the table at 79.2%, 3 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 53 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am154 flights91.6%
- 8am–11am66 flights80.3%
- 11am–2pm64 flights93.7%
- 2pm–5pm59 flights62.1%
- 5pm–8pm206 flights63.4%
- 8pm–5am84 flights41.0%
Scale runs 35% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 41.0% on time, against 93.7% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 206 flights scheduled in it.
Across the year
Southwest on ATL to PHX through the year
June is the worst month at 56.8% on time, 34 points below January, the best at 91.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 66 flights.
Across the week, Saturday is the strongest day at 78.3% on time and Wednesday the weakest at 64.8%. 14 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 8,470 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 48%Late-arriving aircraft
- 29%Carrier
- 19%National Airspace System
- 4%Extreme weather
- 0%Security
48% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 8,470 reported delay minutes here, that single category outweighs weather by 13 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 8,470 reported delay minutes.
Cancellations are rare at 0.32%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
7.3% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
At 1,587 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 77.6% on time across 632 flights, 6 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.
One caution: this is a thin sample. 633 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on ATL to PHX
Put together: treat all of this as provisional. 633 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 72.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 629 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to PHX, every carrier
- Southwest on PHX to ATL, the return leg
- American Airlines on ATL to PHX79.2%
- Delta Air Lines on ATL to PHX76.0%
- Frontier Airlines on ATL to PHX67.8%
- Southwest Airlines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.