OnTimeStats

Historical on-time performance

Boston to Denver

1,754 miData through Dec 2025Source: US DOT · BTS

Flights on BOS–DEN arrive on time 75% of the time over the last 12 months.

On-time rate75%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled0.4%of scheduled flights

based on 3,949 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

  • United Airlines
    On-time79%
    Medianon time
    p9040 min
    Cancel0.2%
    Flights1,967
  • Southwest Airlines
    On-time69%
    Medianon time
    p9065 min
    Cancel0.3%
    Flights945
  • Delta Air Lines
    On-time75%
    Medianon time
    p9035 min
    Cancel0.8%
    Flights387
  • JetBlue Airways
    On-time75%
    Medianon time
    p9040 min
    Cancel0.8%
    Flights650

Why flights run late

Delay causes

  • Airline22%
  • Weather3%
  • Air traffic (NAS)30%
  • Late aircraft46%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly BOS → 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 56% to 85% on time.

  • Mornings85% on time · p90 20 min · 4,606 flights
  • Middays84% on time · p90 20 min · 1,986 flights
  • Afternoons73% on time · p90 45 min · 2,458 flights
  • Overnights62% on time · p90 80 min · 922 flights
  • Evenings56% on time · p90 90 min · 1,141 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 75% to 80% on time.

  • Tuesdays80% on time · p90 30 min · 1,480 flights
  • Wednesdays80% on time · p90 30 min · 1,577 flights
  • Mondays79% on time · p90 40 min · 1,666 flights
  • Saturdays77% on time · p90 40 min · 1,433 flights
  • Sundays77% on time · p90 40 min · 1,626 flights
  • Thursdays76% on time · p90 45 min · 1,655 flights
  • Fridays75% on time · p90 55 min · 1,676 flights
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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.