OnTimeStats

Historical on-time performance

Louisville to Boston

829 miData through Dec 2025Source: US DOT · BTS

Flights on SDF–BOS arrive on time 68% of the time over the last 12 months.

On-time rate68%arrived within 15 min
p90 delay80 min1 in 10 flights is worse (tail risk)
Cancelled1.1%of scheduled flights

based on 633 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Republic Airwaysbest
    On-time70%
    Medianon time
    p9080 min
    Cancel1.2%
    Flights603
  • Envoy Air
    On-time37%
    Median25 min
    p90100 min
    Cancel0.0%
    Flights30

Why flights run late

Delay causes

  • Airline12%
  • Weather13%
  • Air traffic (NAS)54%
  • Late aircraft20%
  • Security0%

Most delay minutes here are attributed to Air traffic (NAS).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly SDF → BOS

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 — 89% on time.

  • Mornings89% on time · p90 10 min · 235 flights
  • Evenings75% on time · p90 45 min · 480 flights
  • Middays75% on time · p90 55 min · 392 flights
  • Afternoons72% on time · p90 70 min · 1,029 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 68% to 83% on time.

  • Saturdays83% on time · p90 35 min · 227 flights
  • Tuesdays79% on time · p90 60 min · 317 flights
  • Wednesdays77% on time · p90 45 min · 317 flights
  • Thursdays74% on time · p90 55 min · 317 flights
  • Mondays74% on time · p90 60 min · 321 flights
  • Fridays73% on time · p90 70 min · 315 flights
  • Sundays68% on time · p90 70 min · 322 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.