OnTimeStats

Historical on-time performance

Boston to Louisville

829 miData through May 2026Source: US DOT · BTS

Flights on BOS–SDF arrive on time 83% of the time over the last 12 months.

On-time rate83%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled1.5%of scheduled flights

based on 587 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Not enough comparable data to name a most-on-time carrier — low-data carriers aren't ranked.

  • Envoy Air
    On-time90%
    Medianon time
    p9010 min
    Cancel0.0%
    Flights60
  • Republic Airways
    On-time82%
    Medianon time
    p9025 min
    Cancel1.7%
    Flights527

Why flights run late

Delay causes

  • Airline37%
  • Weather2%
  • Air traffic (NAS)23%
  • Late aircraft37%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline11%
  • Weather56%
  • Air traffic (NAS)33%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 9 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 BOS → SDF

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

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 69% to 89% on time.

  • Middays89% on time · p90 15 min · 1,227 flights
  • Mornings88% on time · p90 10 min · 443 flights
  • Afternoons85% on time · p90 20 min · 380 flights
  • Overnights69% on time · p90 70 min · 146 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 84% to 89% on time.

  • Wednesdays89% on time · p90 15 min · 324 flights
  • Tuesdays88% on time · p90 10 min · 325 flights
  • Saturdays88% on time · p90 15 min · 250 flights
  • Fridays87% on time · p90 25 min · 326 flights
  • Thursdays86% on time · p90 20 min · 328 flights
  • Mondays85% on time · p90 20 min · 329 flights
  • Sundays84% on time · p90 30 min · 326 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.