Best Time to Fly DSM to STL: On-Time Stats by Hour & Airline
Des Moines International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
403 flights were scheduled from Des Moines (DSM) to St. Louis (STL) in the last 12 months, and 89.2% of those that flew arrived on time, 11.6 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
July has been the best month (95% on time) and Saturday the weakest day of the week (84%).
0.7% of flights were cancelled, versus 1.8% nationally.
DSM 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 | 89.2% | 72 min | 0.7% | 403 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly DSM to STL
On-time arrival % by scheduled departure hour (local time), 1,081 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 94.4% | 1.4% | 216 |
| 6am–7am | 95.7% | 0.7% | 284 |
| 7am–8am | Limited data | 28 | |
| 8am–9am | 92.9% | 0.0% | 42 |
| 9am–10am | Limited data | 5 | |
| 3pm–4pm | 97.0% | 0.0% | 33 |
| 4pm–5pm | 90.2% | 0.6% | 174 |
| 5pm–6pm | 81.4% | 0.0% | 113 |
| 6pm–7pm | 75.1% | 0.5% | 186 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on DSM 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) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 86.4% | -3.5 pts | 1.7% | 60 |
| Summer peak (Jun 15 - Aug 15) | 89.5% | -0.5 pts | 0.0% | 143 |
| All other days | 90.0% | — | 0.5% | 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).