OnTimeStats

Historical on-time performance

St. Louis to Baltimore

737 miData through May 2026Source: 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 delay35 min1 in 10 flights is worse (tail risk)
Cancelled1.2%of scheduled flights

based on 1,288 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
    p9035 min
    Cancel1.2%
    Flights1,288

Why flights run late

Delay causes

  • Airline23%
  • Weather5%
  • Air traffic (NAS)12%
  • Late aircraft60%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather87%
  • Air traffic (NAS)13%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 15 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 STL → BWI

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 10 min · 1,557 flights
  • Middays85% on time · p90 20 min · 508 flights
  • Afternoons73% on time · p90 35 min · 596 flights
  • Evenings70% on time · p90 55 min · 763 flights
  • Overnights62% on time · p90 70 min · 463 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 77% to 85% on time.

  • Tuesdays85% on time · p90 20 min · 521 flights
  • Wednesdays84% on time · p90 25 min · 520 flights
  • Thursdays80% on time · p90 35 min · 576 flights
  • Saturdays80% on time · p90 35 min · 496 flights
  • Fridays79% on time · p90 35 min · 583 flights
  • Sundays78% on time · p90 40 min · 616 flights
  • Mondays77% on time · p90 30 min · 575 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.