Best Time to Fly MCI to STL: On-Time Stats by Hour & Airline
Kansas City International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
1,020 flights were scheduled from Kansas City (MCI) to St. Louis (STL) in the last 12 months, and 86.0% of those that flew arrived on time, 8.4 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Friday was the most reliable day (91% on time) and June the worst month (79%).
The cancellation rate was 0.5% (US average 1.8%).
MCI 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 |
|---|---|---|---|---|
| Southwest Airlines | 86.0% | 53 min | 0.5% | 1,020 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly MCI to STL
On-time arrival % by scheduled departure hour (local time), 2,032 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 96.6% | 1.3% | 238 |
| 6am–7am | 96.5% | 0.0% | 231 |
| 7am–8am | 94.9% | 1.3% | 79 |
| 8am–9am | 91.7% | 0.6% | 171 |
| 9am–10am | Limited data | 6 | |
| 10am–11am | 90.5% | 1.6% | 64 |
| 11am–12pm | 92.9% | 1.6% | 187 |
| 12pm–1pm | 91.7% | 0.8% | 122 |
| 1pm–2pm | 84.1% | 1.1% | 191 |
| 2pm–3pm | 83.3% | 0.0% | 30 |
| 3pm–4pm | 92.4% | 0.0% | 66 |
| 4pm–5pm | 85.3% | 0.0% | 190 |
| 5pm–6pm | 65.6% | 0.0% | 196 |
| 6pm–7pm | 77.7% | 0.8% | 258 |
| 10pm–11pm | Limited data | 3 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on MCI 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) | 88.2% | -0.7 pts | 2.9% | 35 |
| Christmas & New Year (Dec 20 - Jan 3) | 87.5% | -1.4 pts | 0.0% | 80 |
| Summer peak (Jun 15 - Aug 15) | 80.8% | -8.1 pts | 0.5% | 371 |
| All other days | 88.9% | — | 0.8% | 1,546 |
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).