OnTimeStats

Historical on-time performance

Buffalo to Denver

1,359 miData through May 2026Source: US DOT · BTS

Flights on BUF–DEN arrive on time 85% of the time over the last 12 months.

On-time rate85%arrived within 15 min
p90 delay20 min1 in 10 flights is worse (tail risk)
Cancelled0.2%of scheduled flights

based on 453 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.

  • United Airlines
    On-time86%
    Medianon time
    p9020 min
    Cancel0.4%
    Flights275
  • Southwest Airlines
    On-time83%
    Medianon time
    p9025 min
    Cancel0.0%
    Flights178

Why flights run late

Delay causes

  • Airline49%
  • Weather3%
  • Air traffic (NAS)23%
  • Late aircraft25%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline100%
  • Weather0%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 1 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 BUF → DEN

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 59% to 86% on time.

  • Mornings86% on time · p90 20 min · 610 flights
  • Middays84% on time · p90 20 min · 423 flights
  • Afternoons60% on time · p90 50 min · 226 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 67% to 85% on time.

  • Thursdays85% on time · p90 20 min · 183 flights · limited
  • Tuesdays83% on time · p90 20 min · 165 flights · limited
  • Wednesdays83% on time · p90 25 min · 178 flights · limited
  • Sundays79% on time · p90 30 min · 208 flights
  • Mondays77% on time · p90 45 min · 222 flights
  • Fridays77% on time · p90 35 min · 227 flights
  • Saturdays67% on time · p90 50 min · 249 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.