OnTimeStats

Historical on-time performance

Denver to Boston

1,754 miData through May 2026Source: US DOT · BTS

Flights on DEN–BOS arrive on time 71% of the time over the last 12 months.

On-time rate71%arrived within 15 min
p90 delay65 min1 in 10 flights is worse (tail risk)
Cancelled1.1%of scheduled flights

based on 3,883 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-time76%
    Medianon time
    p9055 min
    Cancel0.8%
    Flights1,916
  • Delta Air Lines
    On-time74%
    Medianon time
    p9050 min
    Cancel1.3%
    Flights387
  • JetBlue Airways
    On-time69%
    Medianon time
    p9075 min
    Cancel1.9%
    Flights675
  • Southwest Airlines
    On-time59%
    Median5 min
    p9085 min
    Cancel1.1%
    Flights905

Why flights run late

Delay causes

  • Airline20%
  • Weather1%
  • Air traffic (NAS)43%
  • Late aircraft37%
  • Security0%

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

When flights don't go

Why flights were cancelled

  • Airline11%
  • Weather80%
  • Air traffic (NAS)9%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 44 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 → BOS

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Mornings are the most reliable time of day to fly this route — 80% on time.

  • Mornings80% on time · p90 35 min · 2,701 flights
  • Overnights76% on time · p90 55 min · 1,748 flights
  • Middays68% on time · p90 65 min · 3,344 flights
  • Afternoons63% on time · p90 95 min · 1,390 flights
  • Evenings61% on time · p90 75 min · 2,080 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 67% to 75% on time.

  • Saturdays75% on time · p90 50 min · 1,443 flights
  • Wednesdays74% on time · p90 55 min · 1,589 flights
  • Tuesdays72% on time · p90 60 min · 1,517 flights
  • Sundays69% on time · p90 60 min · 1,678 flights
  • Thursdays67% on time · p90 70 min · 1,688 flights
  • Mondays67% on time · p90 70 min · 1,684 flights
  • Fridays67% on time · p90 70 min · 1,712 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.