St. Louis (STL) to Phoenix (PHX): On-Time Performance
Data through July 2026
St. Louis (STL) to Phoenix (PHX) effectively runs on two schedules. In September 2024, 88% of arrivals were on time; in June 2026 that fell to 58% — a 30-point seasonal swing. Across the full period the route averages 77% on-time against a national 78%. Morning departures also hold up better than evening ones (88% vs 62%), which matters most in the rough months.
- On-time
- 77%
- arrived <15 min late
- Avg delay
- 18 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 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlinesmost reliable | 83% | 17 min | 0.0% | 165 |
| Frontier Airlines | 80% | 32 min | 1.5% | 66 |
| American Airlines | 79% | 30 min | 0.7% | 1,201 |
| Southwest Airlines | 76% | 13 min | 0.5% | 3,357 |
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 (53%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 76% | 21 min |
| Tuesdaybest | 80% | 14 min |
| Wednesday | 80% | 14 min |
| Thursday | 75% | 18 min |
| Friday | 80% | 18 min |
| Saturday | 78% | 16 min |
| Sunday | 75% | 23 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft42%
- Airline operations45%
- National airspace system9%
- Weather3%
Frequently asked questions
- How often are flights from STL to PHX delayed?
- 23% of STL–PHX flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 18 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 (53%). 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 23% of the time.
- How often are STL to PHX flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to PHX?
- June 2026 was the roughest month in this dataset, with only 58% of arrivals on time. The best was September 2024 at 88%. If your dates are flexible, that 30-point gap is worth planning around.
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Based on 4,820 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.