St. Louis (STL) to Phoenix (PHX): On-Time Performance
Data through May 2026
St. Louis (STL) to Phoenix (PHX) effectively runs on two schedules. In September 2024, 88% of arrivals were on time; in July 2024 that fell to 66% — a 22-point seasonal swing. Across the full period the route averages 78% on-time against a national 78%. Morning departures also hold up better than evening ones (88% vs 64%), which matters most in the rough months.
- On-time
- 78%
- arrived <15 min late
- Avg delay
- 17 min
- completed flights
- Cancelled
- 0.6%
- Flights/day
- 6.3
- last 12 months
- Duration
- 3h 24m
- scheduled
- Distance
- 1,262 mi
Best airline from STL to PHX
4 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlinesmost reliable | 83% | 17 min | 0.0% | 165 |
| American Airlines | 80% | 28 min | 0.7% | 1,154 |
| Frontier Airlines | 78% | 32 min | 1.3% | 77 |
| Southwest Airlines | 78% | 13 min | 0.5% | 3,235 |
Monthly on-time trend
Best time to fly from STL to PHX
Aim for departures around 5 a.m. (95% on-time); avoid 10 p.m. departures (55%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 77% | 21 min |
| Tuesday | 80% | 14 min |
| Wednesday | 80% | 14 min |
| Thursday | 76% | 18 min |
| Fridaybest | 81% | 17 min |
| Saturday | 78% | 15 min |
| Sunday | 77% | 18 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft44%
- Airline operations44%
- National airspace system9%
- Weather3%
Frequently asked questions
- How often are flights from STL to PHX delayed?
- 22% of STL–PHX flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 17 minutes.
- Which airline is most reliable from STL to PHX?
- SkyWest Airlines has the best on-time record on this route at 83%, based on 165 flights. 4 airlines flew STL–PHX frequently enough to compare in this period.
- What is the best time of day to fly from STL to PHX?
- Departures around 5 a.m. have the best record (95% on-time), while departures around 10 p.m. have the worst (55%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from STL to PHX?
- The scheduled STL–PHX flight time averages 3h 24m over 1,262 miles. Actual arrival times vary — flights on this route land 15+ minutes late 22% of the time.
- How often are STL to PHX flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to PHX?
- July 2024 was the roughest month in this dataset, with only 66% of arrivals on time. The best was September 2024 at 88%. If your dates are flexible, that 22-point gap is worth planning around.
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Based on 4,666 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.