OnTimeStats

Historical on-time performance

Chicago to Portland

895 miData through Dec 2025Source: US DOT · BTS

Flights on MDW–PWM arrive on time 89% of the time over the last 12 months.

On-time rate89%arrived within 15 min
p90 delay10 min1 in 10 flights is worse (tail risk)
Cancelled0.8%of scheduled flights

based on 123 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time89%
    Medianon time
    p9010 min
    Cancel0.8%
    Flights123

Why flights run late

Delay causes

  • Airline31%
  • Weather0%
  • Air traffic (NAS)44%
  • Late aircraft26%
  • Security0%

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

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly MDW → PWM

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 81% to 83% on time.

  • Evenings83% on time · p90 35 min · 59 flights · limited
  • Mornings83% on time · p90 20 min · 92 flights · limited
  • Middays81% on time · p90 25 min · 266 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 75% to 85% on time.

  • Wednesdays85% on time · p90 15 min · 65 flights · limited
  • Thursdays83% on time · p90 25 min · 66 flights · limited
  • Tuesdays83% on time · p90 15 min · 65 flights · limited
  • Mondays80% on time · p90 30 min · 64 flights · limited
  • Saturdays79% on time · p90 20 min · 66 flights · limited
  • Fridays79% on time · p90 30 min · 66 flights · limited
  • Sundays75% on time · p90 30 min · 64 flights · limited
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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.