OnTimeStats

Historical on-time performance

Baltimore to Grand Rapids

528 miData through May 2026Source: US DOT · BTS

Flights on BWI–GRR arrive on time 78% of the time over the last 12 months.

On-time rate78%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled0.5%of scheduled flights

based on 395 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time78%
    Medianon time
    p9040 min
    Cancel0.5%
    Flights395

Why flights run late

Delay causes

  • Airline30%
  • Weather9%
  • Air traffic (NAS)10%
  • Late aircraft51%
  • Security1%

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 2 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 BWI → GRR

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 71% to 86% on time.

  • Mornings86% on time · p90 15 min · 134 flights · limited
  • Middays83% on time · p90 20 min · 823 flights
  • Afternoons71% on time · p90 40 min · 100 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 75% to 87% on time.

  • Tuesdays87% on time · p90 15 min · 164 flights · limited
  • Wednesdays85% on time · p90 30 min · 164 flights · limited
  • Mondays80% on time · p90 30 min · 166 flights · limited
  • Thursdays78% on time · p90 25 min · 166 flights · limited
  • Fridays78% on time · p90 25 min · 165 flights · limited
  • Sundays77% on time · p90 30 min · 173 flights · limited
  • Saturdays75% on time · p90 35 min · 173 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.