Best Time to Fly STL to DSM: On-Time Stats by Hour & Airline
St Louis Lambert International → Des Moines International
Data through July 2026 · Last updated October 18, 2026
403 flights were scheduled from St. Louis (STL) to Des Moines (DSM) in the last 12 months, and 81.7% of those that flew arrived on time, 4.1 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Monday was the most reliable day (86% on time) and July the worst month (72%).
The cancellation rate was 0.5% (US average 1.8%).
STL to DSM 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 | 81.7% | 46 min | 0.5% | 403 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to DSM
On-time arrival % by scheduled departure hour (local time), 1,081 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | Limited data | 8 | |
| 9am–10am | 89.3% | 0.5% | 198 |
| 10am–11am | 93.1% | 0.0% | 261 |
| 11am–12pm | 90.8% | 1.5% | 66 |
| 12pm–1pm | Limited data | 1 | |
| 1pm–2pm | Limited data | 24 | |
| 2pm–3pm | Limited data | 22 | |
| 8pm–9pm | 80.7% | 1.3% | 157 |
| 9pm–10pm | 73.8% | 0.8% | 125 |
| 10pm–11pm | 69.4% | 0.9% | 219 |
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 DSM
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) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 70.0% | -14.7 pts | 0.0% | 60 |
| Summer peak (Jun 15 - Aug 15) | 79.0% | -5.7 pts | 0.0% | 143 |
| All other days | 84.7% | — | 0.6% | 852 |
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).