STL → PHX Flight Reliability

Right now

Origin · STLNo disruption reported

Aviation weather is not currently a factor.

Updated 12:51 UTC

St. Louis airport profile →

Destination · PHXNo disruption reported

Aviation weather is not currently a factor.

Updated 12:51 UTC

Phoenix airport profile →

Route reliability

July 2023 – July 2026

Route Reliability Score

68/ 100Good

Better than 57% of comparable major US routes (4,598 compared)

Calculated from 6,945 flights. How this is calculated

On-time arrivals

77.8%

5,369 of 6,898

Cancellation rate

0.53%

37 cancelled

Median arrival delay

-4 min

Average 9.2 min

Severe delays

6.5%

60+ minutes late

Delay when late

72 min

Average, when 15+ min late

Flights analyzed

6,945

3 carriers

STL → PHX arrives on time 77.8% of the time; the return trip, PHX → STL, arrives on time 79.5% of the time.

STL → PHX spends 19.3 minutes on the ground on a 1,262-mile trip: 12.4 minutes from pushback to wheels-up at STL and 6.8 minutes from touchdown to gate at PHX.

Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026

What stands out

On-time performance swings unusually widely by time of day here, wider than 96% of 4,023 comparable routes.

88.9% on time for 5–9 AM departures, against 55.1% for 9 PM–5 AM.

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,023 in the comparison.

What sets this route apart

Where STL to PHX differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.

STL to PHX struggles most at 10 PM: 53.6% of its flights scheduled then arrive on time, 10.3 points behind the 63.9% on routes of similar length at the same hour. Against all other routes the gap is 18.1 points.

STL to PHX is at its best against routes of similar length for flights scheduled at 9 AM: 91.3% arrive on time, 7.9 points ahead of the 83.4% those routes manage at that hour. Against all other routes the gap is 7 points.

January is kinder to STL to PHX than to routes of similar length: 82.2% on time against 77.7%, 4.5 points better.

American Airlines does better on STL to PHX than on its routes of similar length: 81.1% on time here, 74.8% there, 6.3 points apart. Against all other routes the gap is 6 points.

STL to PHX against comparable routes

July 2023 – July 2026

Where STL to PHX differs most from comparable routes, with the group each figure is compared with and the flights behind it
Measure	This route	Compared with	Them	Gap	Flights behind it
Hour: 10 PM departures	53.6%	routes of similar length	63.9%	−10.3 pts	207 here, 19,175 there
Hour: 9 AM departures	91.3%	routes of similar length	83.4%	+7.9 pts	320 here, 103,896 there
Month: January	82.2%	routes of similar length	77.7%	+4.5 pts	563 here, 144,358 there
Airline: American Airlines	81.1%	routes of similar length	74.8%	+6.3 pts	1,860 here, 419,524 there

Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,262 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.

When it goes wrong

July 2023 – July 2026

One arrival in ten is worse than

40 min late

against a median of 4 min early

Arrived an hour or more late6.5%

Typical delay when late72 min

Cancelled0.53%

Landed somewhere else0.14%

Percentiles over 6,945 operations; cancelled and diverted flights are counted separately.

Will your connection be tight enough?

Layovers at PHX after arriving from STL.

Connection buffer and chance of missing by layover length, STL → PHX arrivals
Connection time	Chance of missing	Reads as
30 min	42%	Likely to miss
45 min	21%	High risk
60 min	13%	Some risk
90 min	6.4%	Some risk
120 min	3.8%	Low risk

This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.53% of the time and diverts 0.14% of the time, which a late arrival never shows up in.

Chance of missing is the share of 6,898 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.

The worst tenth of arrivals on this route land at least 40 minutes late (90th-percentile gate arrival delay), over 6,945 operations.

Any other layover length: connection checker.

Best time to fly

STL → PHX flights departing 5–9 AM arrived on time 88.9% of the time, against 55.1% for 9 PM–5 AM departures, a gap of 33.8 percentage points.

By departure window

5–9 AM88.9%

9 AM–12 PM87.3%

12–3 PM78.7%

3–6 PM67.7%

6–9 PM66.8%

9 PM–5 AM55.1%

By departure hour

12 AM

3 AM

6 AM

9 AM

12 PM

3 PM

6 PM

9 PM

Why STL → PHX runs late

July 2023 – July 2026

Late-arriving aircraft44.0%

the inbound aircraft was late, so this flight started late

The airline43.9%

crew, maintenance, boarding and fueling, all within the carrier’s control

Air traffic control9.0%

airspace and airport capacity, including weather-driven flow control

Weather2.9%

weather severe enough to stop this flight specifically

Security0.1%

screening or terminal security incidents

Share of the delay minutes US DOT attributed to each cause for STL → PHX. Only delays of 15 minutes or more are attributed.

Late-arriving aircraft is the largest cause on STL → PHX, at 44.0%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 88.9% of the time and 9 PM–5 AM departures 55.1%.

Airlines on this route

Carriers with at least 200 flights, by the airline that operated each one.

Airlines on this route
Carrier	Flights	On time	Cancelled	Median delay	Severe
Southwest Airlines	4,690	76.1%	0.51%	-2 min	5.7%
American Airlines	1,877	81.1%	0.64%	-7 min	8.5%
SkyWest Airlines	202	83.7%	0.00%	-5 min	3.5%

Southwest Airlines flew 69.3% of the 6,769 flights listed.

SkyWest Airlines arrived on time 7.6 percentage points more often than Southwest Airlines on this route.

Flights on this route

Flight numbers with at least 600 operations here and still on the schedule.

Flights on this route
Flight	Scheduled	Operations	On time
AA2574 American Airlines	8:00 AM	994	83.3%

Weekly and seasonal patterns

By day of week

Mon77.1%

Tue80.6%

Wed80.6%

Thu75.8%

Fri78.0%

Sat77.6%

Sun75.3%

Tuesday is historically the most reliable day and Sunday the least, a gap of 5.3 percentage points.

By month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

June is historically the weakest month and February the strongest, a spread of 15.0 percentage points.

Reliability over time

July 2023 – July 2026

24

25

26

Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 74.7% against 81.4% in the 12 months before — declining by 6.7 percentage points.

Data and methodology

Calculated by FlyerIntel from 6,945 STL → PHX flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.

Full methodology · Data sources · Report a problem

Analysis last recomputed September 26, 2026

STL airport PHX airport Return direction PHX → STL

STL→PHX

Right now

Route reliability

What stands out

What sets this route apart

STL to PHX against comparable routes

When it goes wrong

Will your connection be tight enough?

Best time to fly

By departure window

By departure hour

Why STL → PHX runs late

Airlines on this route

Flights on this route

Weekly and seasonal patterns

By day of week

By month

Reliability over time

Data and methodology