OnTimeStats

Historical on-time performance

San Jose to Chicago

1,829 miData through May 2026Source: US DOT · BTS

Flights on SJC–ORD arrive on time 90% of the time over the last 12 months.

On-time rate90%arrived within 15 min
p90 delay10 min1 in 10 flights is worse (tail risk)
Cancelled1.2%of scheduled flights

based on 244 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlines
    On-time90%
    Medianon time
    p9010 min
    Cancel1.2%
    Flights244

Why flights run late

Delay causes

  • Airline23%
  • Weather0%
  • Air traffic (NAS)35%
  • Late aircraft41%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline33%
  • Weather67%
  • Air traffic (NAS)0%
  • 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 SJC → ORD

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 89% to 92% on time.

  • Mornings92% on time · p90 10 min · 844 flights
  • Overnights89% on time · p90 10 min · 101 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 87% to 94% on time.

  • Sundays94% on time · p90 10 min · 134 flights · limited
  • Wednesdays93% on time · p90 5 min · 132 flights · limited
  • Thursdays93% on time · p90 5 min · 142 flights · limited
  • Mondays92% on time · p90 10 min · 142 flights · limited
  • Fridays91% on time · p90 10 min · 145 flights · limited
  • Tuesdays89% on time · p90 15 min · 130 flights · limited
  • Saturdays87% on time · p90 10 min · 135 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.