OnTimeStats

Historical on-time performance

Denver to Buffalo

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

Flights on DEN–BUF arrive on time 61% of the time over the last 12 months.

On-time rate61%arrived within 15 min
p90 delay85 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-time67%
    Medianon time
    p9090 min
    Cancel0.0%
    Flights275
  • Southwest Airlines
    On-time53%
    Median10 min
    p9080 min
    Cancel0.6%
    Flights178

Why flights run late

Delay causes

  • Airline22%
  • Weather2%
  • Air traffic (NAS)19%
  • Late aircraft58%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather100%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Weather. 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 DEN → BUF

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 54% to 79% on time.

  • Mornings79% on time · p90 20 min · 149 flights · limited
  • Middays73% on time · p90 40 min · 249 flights
  • Afternoons63% on time · p90 45 min · 122 flights · limited
  • Evenings54% on time · p90 90 min · 857 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 53% to 69% on time.

  • Saturdays69% on time · p90 45 min · 249 flights
  • Wednesdays64% on time · p90 80 min · 170 flights · limited
  • Sundays62% on time · p90 80 min · 201 flights
  • Fridays59% on time · p90 60 min · 227 flights
  • Tuesdays58% on time · p90 75 min · 156 flights · limited
  • Mondays58% on time · p90 85 min · 222 flights
  • Thursdays53% on time · p90 80 min · 183 flights · limited

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.