OnTimeStats

Historical on-time performance

Chicago to San Antonio

1,041 miData through May 2026Source: US DOT · BTS

Flights on ORD–SAT arrive on time 72% of the time over the last 12 months.

On-time rate72%arrived within 15 min
p90 delay60 min1 in 10 flights is worse (tail risk)
Cancelled1.7%of scheduled flights

based on 1,684 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-time75%
    Medianon time
    p9055 min
    Cancel1.0%
    Flights811
  • Envoy Air
    On-time74%
    Medianon time
    p9050 min
    Cancel2.5%
    Flights322
  • American Airlines
    On-time68%
    Medianon time
    p9075 min
    Cancel2.4%
    Flights551

Why flights run late

Delay causes

  • Airline24%
  • Weather5%
  • Air traffic (NAS)16%
  • Late aircraft54%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline7%
  • Weather79%
  • Air traffic (NAS)14%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 29 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 ORD → SAT

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 — 82% on time.

  • Mornings82% on time · p90 30 min · 1,651 flights
  • Middays78% on time · p90 45 min · 884 flights
  • Evenings70% on time · p90 60 min · 765 flights
  • Afternoons69% on time · p90 60 min · 311 flights
  • Overnights64% on time · p90 75 min · 1,290 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 71% to 77% on time.

  • Tuesdays77% on time · p90 60 min · 641 flights
  • Thursdays76% on time · p90 50 min · 747 flights
  • Wednesdays75% on time · p90 55 min · 667 flights
  • Mondays74% on time · p90 50 min · 748 flights
  • Saturdays73% on time · p90 65 min · 603 flights
  • Fridays71% on time · p90 60 min · 750 flights
  • Sundays71% on time · p90 50 min · 747 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.