Carrier route record
WNPHX→ATL
Southwest Airlines · Phoenix to Atlanta
- Flights
- 632
- 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 PHX to ATL lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about 40 minutes on average. That is a workable record, not a spotless one. That rests on 632 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 2,303 at 87.0% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on PHX to ATL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.6%
Arrivals under 15 minutes late, of 630 completed flights
Avg delay
40 min
Across delayed arrivals only, not all flights
Cancelled
0.16%
National rate is 1.81%
Whole route
82.7%
Every carrier on PHX to ATL, 3,764 flights
These figures cover 632 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 PHX to ATL
Southwest flew 632 of the 3,764 flights on PHX to ATL, about 17% of it. Its 77.6% on time is 5 points worse than the route as a whole, which runs 82.7%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Delta at 87.0% to Frontier at 72.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.0% of the time; American Airlines manages 75.5%. Sample sizes sit next to every figure, because a two-point gap across 614 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 2,303 | 87.0% | 97 min | 0.91% | A+ |
| Southwest Airlines (this page) | 632 | 77.6% | 40 min | 0.16% | B+ |
| American Airlines | 614 | 75.5% | 66 min | 0.49% | B+ |
| Frontier Airlinesthin sample | 215 | 72.2% | 74 min | 0.93% | C+ |
Delta leads American by 12 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
When Southwest runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 632 flights.
- 5am–8am29 flights—
- 8am–11am278 flights82.3%
- 11am–2pm59 flights74.6%
- 2pm–5pm18 flights—
- 5pm–8pm21 flights—
- 8pm–5am227 flights77.9%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 74.6% on time against 82.3% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 278 flights scheduled in it.
Across the year
Southwest on PHX to ATL through the year
June is the worst month at 67.6% on time, 20 points below July, the best at 87.9%. 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, Monday is the strongest day at 82.4% on time and Sunday the weakest at 72.2%. 10 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 43% of the 5,688 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.
- 43%Late-arriving aircraft
- 40%Carrier
- 17%National Airspace System
- 0%Security
- 0%Extreme weather
43% 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 5,688 reported delay minutes here, that single category outweighs weather by 43 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 5,688 reported delay minutes.
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,258 of the 5,688 delay minutes reported here.
Cancellations are rare at 0.16%, 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
Badly late arrivals are rare here: only 4.1% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 72.0% on time across 633 flights, 6 points below 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. 632 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 PHX to ATL
Put together: treat all of this as provisional. 632 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 77.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 630 completed flights over 12 months sit behind that.
Related
Where to go next
- PHX to ATL, every carrier
- Southwest on ATL to PHX, the return leg
- Delta Air Lines on PHX to ATL87.0%
- American Airlines on PHX to ATL75.5%
- Frontier Airlines on PHX to ATL72.2%
- Southwest Airlines network-wide record
- Phoenix Sky Harbor International (PHX) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.