OnTimeStats

Historical on-time performance

Des Moines to St. Louis

259 miData through May 2026Source: US DOT · BTS

Flights on DSM–STL arrive on time 89% of the time over the last 12 months.

On-time rate89%arrived within 15 min
p90 delay15 min1 in 10 flights is worse (tail risk)
Cancelled0.6%of scheduled flights

based on 508 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time89%
    Medianon time
    p9015 min
    Cancel0.6%
    Flights508

Why flights run late

Delay causes

  • Airline26%
  • Weather16%
  • Air traffic (NAS)23%
  • Late aircraft35%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather67%
  • Air traffic (NAS)33%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 3 cancellations with a reported cause (BTS reports causes from June 2003).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly DSM → STL

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Mornings are the most reliable time of day to fly this route — 92% on time.

  • Mornings92% on time · p90 5 min · 1,002 flights
  • Afternoons83% on time · p90 25 min · 290 flights
  • Evenings75% on time · p90 35 min · 582 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 79% to 91% on time.

  • Tuesdays91% on time · p90 10 min · 288 flights
  • Wednesdays88% on time · p90 20 min · 288 flights
  • Fridays86% on time · p90 20 min · 286 flights
  • Mondays85% on time · p90 20 min · 288 flights
  • Saturdays85% on time · p90 25 min · 157 flights · limited
  • Thursdays84% on time · p90 25 min · 285 flights
  • Sundays79% on time · p90 25 min · 285 flights

Keep exploring

Related pages

Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.