OnTimeStats

Historical on-time performance

Chicago to Louisville

271 miData through Dec 2025Source: US DOT · BTS

Flights on MDW–SDF arrive on time 78% of the time over the last 12 months.

On-time rate78%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled1.0%of scheduled flights

based on 1,001 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time78%
    Medianon time
    p9040 min
    Cancel1.0%
    Flights1,001

Why flights run late

Delay causes

  • Airline25%
  • Weather3%
  • Air traffic (NAS)10%
  • Late aircraft62%
  • 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 MDW → SDF

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

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 64% to 89% on time.

  • Middays89% on time · p90 15 min · 705 flights
  • Mornings88% on time · p90 15 min · 650 flights
  • Afternoons79% on time · p90 35 min · 661 flights
  • Evenings72% on time · p90 50 min · 480 flights
  • Overnights64% on time · p90 70 min · 607 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 75% to 84% on time.

  • Tuesdays84% on time · p90 25 min · 463 flights
  • Wednesdays81% on time · p90 30 min · 466 flights
  • Mondays80% on time · p90 35 min · 476 flights
  • Saturdays79% on time · p90 35 min · 313 flights
  • Thursdays77% on time · p90 35 min · 475 flights
  • Fridays76% on time · p90 40 min · 476 flights
  • Sundays75% on time · p90 45 min · 434 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.