OnTimeStats

Historical on-time performance

Seattle to San Antonio

1,774 miData through May 2026Source: US DOT · BTS

Flights on SEA–SAT arrive on time 74% of the time over the last 12 months.

On-time rate74%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled1.1%of scheduled flights

based on 530 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Alaska Airlines
    On-time74%
    Medianon time
    p9035 min
    Cancel1.1%
    Flights530

Why flights run late

Delay causes

  • Airline38%
  • Weather0%
  • Air traffic (NAS)12%
  • Late aircraft48%
  • Security1%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline83%
  • Weather0%
  • Air traffic (NAS)17%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 6 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 → SAT

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Overnights are the most reliable time of day to fly this route — 79% on time.

  • Overnights79% on time · p90 25 min · 539 flights
  • Middays73% on time · p90 35 min · 1,018 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 70% to 83% on time.

  • Tuesdays83% on time · p90 20 min · 220 flights
  • Wednesdays79% on time · p90 20 min · 219 flights
  • Thursdays78% on time · p90 35 min · 268 flights
  • Mondays76% on time · p90 35 min · 250 flights
  • Fridays73% on time · p90 35 min · 269 flights
  • Saturdays72% on time · p90 40 min · 213 flights
  • Sundays70% on time · p90 30 min · 268 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.