OnTimeStats

Historical on-time performance

Grand Rapids to Denver

1,015 miData through May 2026Source: US DOT · BTS

Flights on GRR–DEN arrive on time 80% of the time over the last 12 months.

On-time rate80%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled0.3%of scheduled flights

based on 1,034 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.

  • Southwest Airlines
    On-time83%
    Medianon time
    p9025 min
    Cancel0.0%
    Flights306
  • United Airlines
    On-time79%
    Medianon time
    p9035 min
    Cancel0.4%
    Flights728

Why flights run late

Delay causes

  • Airline40%
  • Weather2%
  • Air traffic (NAS)33%
  • Late aircraft24%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather67%
  • Air traffic (NAS)33%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 3 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 GRR → 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 68% to 86% on time.

  • Mornings86% on time · p90 20 min · 1,386 flights
  • Middays83% on time · p90 20 min · 293 flights
  • Afternoons76% on time · p90 35 min · 1,645 flights
  • Overnights72% on time · p90 80 min · 315 flights
  • Evenings68% on time · p90 55 min · 203 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 78% to 82% on time.

  • Tuesdays82% on time · p90 30 min · 494 flights
  • Wednesdays80% on time · p90 30 min · 512 flights
  • Sundays80% on time · p90 35 min · 597 flights
  • Thursdays79% on time · p90 35 min · 519 flights
  • Mondays79% on time · p90 40 min · 556 flights
  • Fridays78% on time · p90 40 min · 561 flights
  • Saturdays78% on time · p90 35 min · 603 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.