OnTimeStats

Historical on-time performance

Denver to Louisville

1,024 miData through May 2026Source: US DOT · BTS

Flights on DEN–SDF arrive on time 74% of the time over the last 12 months.

On-time rate74%arrived within 15 min
p90 delay50 min1 in 10 flights is worse (tail risk)
Cancelled0.7%of scheduled flights

based on 1,078 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlinesbest
    On-time79%
    Medianon time
    p9040 min
    Cancel0.5%
    Flights731
  • Southwest Airlines
    On-time63%
    Median5 min
    p9070 min
    Cancel1.2%
    Flights347

Why flights run late

Delay causes

  • Airline29%
  • Weather2%
  • Air traffic (NAS)13%
  • Late aircraft56%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline25%
  • Weather63%
  • Air traffic (NAS)13%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 8 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 DEN → SDF

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 — 85% on time.

  • Mornings85% on time · p90 20 min · 1,028 flights
  • Middays75% on time · p90 30 min · 370 flights
  • Afternoons71% on time · p90 35 min · 318 flights
  • Evenings65% on time · p90 75 min · 1,466 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 67% to 77% on time.

  • Saturdays77% on time · p90 45 min · 472 flights
  • Mondays75% on time · p90 40 min · 462 flights
  • Tuesdays74% on time · p90 55 min · 456 flights
  • Wednesdays74% on time · p90 45 min · 455 flights
  • Fridays71% on time · p90 55 min · 465 flights
  • Sundays71% on time · p90 55 min · 501 flights
  • Thursdays67% on time · p90 65 min · 468 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.