Best Time to Fly STL to PHX: On-Time Stats by Hour & Airline
St Louis Lambert International → Phoenix Sky Harbor International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 74.7% of St. Louis (STL) to Phoenix (PHX) flights arrived on time (2,315 scheduled flights). That is 2.9 points below the national average of 77.6%.
Envoy Air was the most punctual of the 4 airlines on the route at 100.0%, while Southwest Airlines trailed at 71.4%.
January has been the best month (85% on time) and Sunday the weakest day of the week (75%).
0.5% of flights were cancelled, versus 1.8% nationally.
STL to PHX on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Envoy Air | 100.0% | — | 0.0% | 30 |
| Frontier Airlines | 82.7% | 210 min | 1.9% | 53 |
| American Airlines | 81.0% | 184 min | 1.0% | 586 |
| Southwest Airlines | 71.4% | 50 min | 0.3% | 1,619 |
| SkyWest Airlines | Limited data | 27 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to PHX
On-time arrival % by scheduled departure hour (local time), 4,610 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 95.1% | 0.6% | 351 |
| 6am–7am | 92.9% | 0.7% | 285 |
| 7am–8am | 83.5% | 0.7% | 579 |
| 8am–9am | 88.6% | 1.0% | 311 |
| 9am–10am | 91.7% | 0.0% | 228 |
| 10am–11am | 84.3% | 2.5% | 118 |
| 11am–12pm | 81.3% | 0.0% | 140 |
| 12pm–1pm | 96.4% | 1.8% | 57 |
| 1pm–2pm | 73.2% | 0.0% | 251 |
| 2pm–3pm | 78.5% | 0.4% | 707 |
| 3pm–4pm | 82.0% | 0.0% | 133 |
| 4pm–5pm | 67.6% | 0.9% | 106 |
| 5pm–6pm | 64.8% | 0.0% | 239 |
| 6pm–7pm | 64.0% | 0.8% | 374 |
| 7pm–8pm | 57.4% | 0.0% | 109 |
| 8pm–9pm | 68.2% | 0.4% | 268 |
| 9pm–10pm | 57.9% | 1.7% | 237 |
| 10pm–11pm | 57.3% | 0.0% | 117 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on STL to PHX
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 71.3% | -8.3 pts | 0.0% | 101 |
| Christmas & New Year (Dec 20 - Jan 3) | 79.2% | -0.4 pts | 0.0% | 212 |
| Summer peak (Jun 15 - Aug 15) | 70.8% | -8.9 pts | 0.3% | 712 |
| All other days | 79.6% | — | 0.7% | 3,585 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).