OnTimeStats

Historical on-time performance

St. Louis to Baltimore

737 miData through Dec 2025Source: US DOT · BTS

Flights on STL–BWI arrive on time 80% of the time over the last 12 months.

On-time rate80%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled1.4%of scheduled flights

based on 1,318 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time80%
    Medianon time
    p9040 min
    Cancel1.4%
    Flights1,318

Why flights run late

Delay causes

  • Airline22%
  • Weather7%
  • Air traffic (NAS)16%
  • Late aircraft56%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly STL → BWI

All airlines · rolling 36 months (2023-01 .. 2025-12).

Best time of day

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

  • Mornings92% on time · p90 10 min · 1,547 flights
  • Middays86% on time · p90 20 min · 509 flights
  • Afternoons75% on time · p90 30 min · 558 flights
  • Evenings70% on time · p90 45 min · 777 flights
  • Overnights63% on time · p90 65 min · 480 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 79% to 84% on time.

  • Tuesdays84% on time · p90 20 min · 531 flights
  • Wednesdays83% on time · p90 25 min · 532 flights
  • Fridays80% on time · p90 25 min · 570 flights
  • Thursdays80% on time · p90 30 min · 563 flights
  • Saturdays80% on time · p90 35 min · 497 flights
  • Sundays79% on time · p90 35 min · 610 flights
  • Mondays79% on time · p90 25 min · 568 flights
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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.