Best Time to Fly DEN to STL: On-Time Stats by Hour & Airline
Denver International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
3,695 flights were scheduled from Denver (DEN) to St. Louis (STL) in the last 12 months, and 78.0% of those that flew arrived on time, in line with the US average of 77.6%.
Frontier Airlines was the most punctual of the 4 airlines on the route at 83.8%, while Southwest Airlines trailed at 76.5%.
October has been the best month (87% on time) and Sunday the weakest day of the week (75%).
0.5% of flights were cancelled, versus 1.8% nationally.
DEN to STL 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 |
|---|---|---|---|---|
| Frontier Airlines | 83.8% | 49 min | 0.3% | 291 |
| SkyWest Airlines | 82.4% | 40 min | 0.9% | 110 |
| United Airlines | 79.1% | 63 min | 0.3% | 1,100 |
| Southwest Airlines | 76.5% | 59 min | 0.6% | 2,194 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly DEN to STL
On-time arrival % by scheduled departure hour (local time), 7,392 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 93.8% | 0.0% | 225 |
| 6am–7am | 93.8% | 0.5% | 569 |
| 7am–8am | 91.8% | 0.3% | 378 |
| 8am–9am | 93.8% | 0.4% | 275 |
| 9am–10am | 85.9% | 0.2% | 798 |
| 10am–11am | 86.8% | 0.5% | 588 |
| 11am–12pm | 85.1% | 0.0% | 235 |
| 12pm–1pm | 79.5% | 0.8% | 123 |
| 1pm–2pm | 84.0% | 0.4% | 931 |
| 2pm–3pm | 73.7% | 0.0% | 270 |
| 3pm–4pm | 65.9% | 0.3% | 294 |
| 4pm–5pm | 70.1% | 0.8% | 253 |
| 5pm–6pm | 67.0% | 0.3% | 749 |
| 6pm–7pm | 65.6% | 0.8% | 499 |
| 7pm–8pm | 56.5% | 1.8% | 393 |
| 8pm–9pm | 64.4% | 1.2% | 604 |
| 9pm–10pm | 62.1% | 0.6% | 163 |
| 10pm–11pm | 71.4% | 4.4% | 45 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on DEN to STL
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) | 76.2% | -4.6 pts | 0.7% | 145 |
| Christmas & New Year (Dec 20 - Jan 3) | 80.5% | -0.4 pts | 0.0% | 282 |
| Summer peak (Jun 15 - Aug 15) | 67.0% | -13.8 pts | 0.6% | 1,433 |
| All other days | 80.9% | — | 0.6% | 5,532 |
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).