St. Louis (STL) to Des Moines (DSM): On-Time Performance
Data through May 2026
The calendar drives reliability on STL–DSM. November 2024 flights landed on schedule 95% of the time, but December 2025 dropped to 67% — a gap of 28 points. Across the full period the route averages 82% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 72%), which matters most in the rough months.
- On-time
- 82%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.6%
- Flights/day
- 1.4
- last 12 months
- Duration
- 1h 9m
- scheduled
- Distance
- 259 mi
Monthly on-time trend
Best time to fly from STL to DSM
Aim for departures around 10 a.m. (92% on-time); avoid 10 p.m. departures (67%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Mondaybest | 84% | 10 min |
| Tuesday | 83% | 8 min |
| Wednesdaybest | 84% | 12 min |
| Thursday | 79% | 12 min |
| Friday | 81% | 9 min |
| Saturday | 82% | 10 min |
| Sunday | 79% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft58%
- Airline operations28%
- National airspace system11%
- Weather3%
Frequently asked questions
- How often are flights from STL to DSM delayed?
- 19% of STL–DSM flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 10 minutes.
- What is the best time of day to fly from STL to DSM?
- Departures around 10 a.m. have the best record (92% on-time), while departures around 10 p.m. have the worst (67%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from STL to DSM?
- The scheduled STL–DSM flight time averages 1h 9m over 259 miles. Actual arrival times vary — flights on this route land 15+ minutes late 19% of the time.
- How often are STL to DSM flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to DSM?
- December 2025 was the roughest month in this dataset, with only 67% of arrivals on time. The best was November 2024 at 95%. If your dates are flexible, that 28-point gap is worth planning around.
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Based on 1,194 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.