OnTimeStats

Historical on-time performance

San Antonio to Houston

191 miData through May 2026Source: US DOT · BTS

Flights on SAT–IAH arrive on time 81% of the time over the last 12 months.

On-time rate81%arrived within 15 min
p90 delay30 min1 in 10 flights is worse (tail risk)
Cancelled1.0%of scheduled flights

based on 2,361 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlines
    On-time81%
    Medianon time
    p9030 min
    Cancel1.0%
    Flights2,361

Why flights run late

Delay causes

  • Airline22%
  • Weather2%
  • Air traffic (NAS)47%
  • Late aircraft29%
  • Security0%

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

When flights don't go

Why flights were cancelled

  • Airline30%
  • Weather61%
  • Air traffic (NAS)9%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 23 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 SAT → IAH

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 76% to 86% on time.

  • Mornings86% on time · p90 15 min · 2,878 flights
  • Middays84% on time · p90 30 min · 791 flights
  • Afternoons78% on time · p90 45 min · 1,436 flights
  • Evenings76% on time · p90 45 min · 1,737 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 79% to 85% on time.

  • Saturdays85% on time · p90 25 min · 951 flights
  • Tuesdays83% on time · p90 25 min · 982 flights
  • Wednesdays83% on time · p90 25 min · 986 flights
  • Mondays83% on time · p90 30 min · 992 flights
  • Thursdays80% on time · p90 35 min · 981 flights
  • Sundays79% on time · p90 35 min · 957 flights
  • Fridays79% on time · p90 40 min · 994 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.