Route on-time record
STL to DSM: most on-time flights and the best time to fly
St Louis (St. Louis Lambert International Airport) to Des Moines (Des Moines International Airport). 516 nonstop flights in Jun 2025 to May 2026, 81% arrived within 15 minutes and 0.4% were cancelled.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
STL → DSM
St Louis to Des Moines: 516 nonstop flights a year
On time (12 months)
81%
Cancelled
0.4%
avg delay 10 min
Best time to leave
9 AM to noon
93% on time vs 70% after 9 PM
Most reliable airline
Southwest
81% chance on time
Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
None of this route’s recently flown flight numbers operated on that weekday. Try another date, or see the airlines and times below.
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines81%
516 flights · 81% on time as flown · 0.4% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- 9 AM to noon93%
235 flights · avg delay 5 min
- Noon to 3 PM76%
33 flights · avg delay 12 min
- 6 to 9 PM71%
63 flights · avg delay 10 min
- After 9 PM70%
177 flights · avg delay 17 min
Best day: Wednesday (83%). Worst: Sunday (75%).
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Late-arriving aircraft63%
- Airline (crew, maintenance, boarding)25%
- Air traffic control and airport volume10%
- Severe weather2%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
STL to DSM questions
- What time of day is best to fly STL to DSM?
- 9 AM to noon: 93% of flights arrived on time, against 70% for departures after 9 PM.
- Which airline is most on time from STL to DSM?
- Southwest, with a season-adjusted 81% chance of operating and arriving on time over 516 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on STL to DSM?
- July (69% on time); the best was October (89%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from STL
- DSM to STL (return)
- STL to ATL 85%
- STL to DEN 75%
- STL to ORD 71%
- STL to LGA 75%
- STL to MCO 78%
- STL to DCA 73%
- STL to DFW 74%
- STL to PHX 76%
- STL to LAS 79%
- STL to DAL 77%
- STL to DTW 83%
- STL to MSP 80%
Live status: FAA delays and ground stops