OnTimeStats

Historical on-time performance

Seattle to Chicago

1,721 miData through May 2026Source: US DOT · BTS

Flights on SEA–ORD arrive on time 73% of the time over the last 12 months.

On-time rate73%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled1.2%of scheduled flights

based on 5,555 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-time78%
    Medianon time
    p9035 min
    Cancel0.9%
    Flights1,539
  • Delta Air Lines
    On-time76%
    Medianon time
    p9045 min
    Cancel1.0%
    Flights898
  • Alaska Airlines
    On-time71%
    Medianon time
    p9045 min
    Cancel0.9%
    Flights1,798
  • American Airlines
    On-time69%
    Medianon time
    p9065 min
    Cancel2.0%
    Flights1,320

Why flights run late

Delay causes

  • Airline33%
  • Weather3%
  • Air traffic (NAS)31%
  • Late aircraft33%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline28%
  • Weather55%
  • Air traffic (NAS)17%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 65 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 SEA → ORD

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 — 84% on time.

  • Mornings84% on time · p90 20 min · 4,195 flights
  • Overnights79% on time · p90 35 min · 2,012 flights
  • Early mornings78% on time · p90 40 min · 724 flights
  • Evenings78% on time · p90 40 min · 2,447 flights
  • Afternoons70% on time · p90 50 min · 1,192 flights
  • Middays69% on time · p90 45 min · 5,066 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 74% to 80% on time.

  • Wednesdays80% on time · p90 35 min · 2,176 flights
  • Tuesdays79% on time · p90 35 min · 2,187 flights
  • Saturdays79% on time · p90 35 min · 1,963 flights
  • Thursdays76% on time · p90 35 min · 2,347 flights
  • Fridays74% on time · p90 40 min · 2,351 flights
  • Sundays74% on time · p90 45 min · 2,280 flights
  • Mondays74% on time · p90 45 min · 2,332 flights

Keep exploring

Related pages

Delay predictorfor this route→SEA airportSeattle→ORD airportChicago→Alaska Airlinesairline profile→United Airlinesairline profile→American Airlinesairline profile→Seasonal delay patternsguide→

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.