OnTimeStats

Historical on-time performance

Buffalo to Denver

1,359 miData through Dec 2025Source: US DOT · BTS

Flights on BUF–DEN arrive on time 84% of the time over the last 12 months.

On-time rate84%arrived within 15 min
p90 delay20 min1 in 10 flights is worse (tail risk)
Cancelled0.2%of scheduled flights

based on 422 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlinesbest
    On-time89%
    Medianon time
    p9015 min
    Cancel0.5%
    Flights183
  • Southwest Airlines
    On-time80%
    Medianon time
    p9030 min
    Cancel0.0%
    Flights239

Why flights run late

Delay causes

  • Airline44%
  • Weather3%
  • Air traffic (NAS)28%
  • Late aircraft25%
  • Security0%

Most delay minutes here are attributed to Airline.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly BUF → DEN

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 59% to 88% on time.

  • Mornings88% on time · p90 15 min · 498 flights
  • Middays85% on time · p90 20 min · 413 flights
  • Overnights63% on time · p90 55 min · 54 flights · limited
  • Afternoons60% on time · p90 50 min · 244 flights
  • Evenings59% on time · p90 100 min · 138 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 65% to 86% on time.

  • Tuesdays86% on time · p90 15 min · 153 flights · limited
  • Thursdays84% on time · p90 25 min · 174 flights · limited
  • Wednesdays84% on time · p90 20 min · 164 flights · limited
  • Sundays79% on time · p90 30 min · 197 flights · limited
  • Fridays77% on time · p90 35 min · 212 flights
  • Mondays77% on time · p90 45 min · 211 flights
  • Saturdays65% on time · p90 45 min · 236 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.