OnTimeStats

Historical on-time performance

Houston to Seattle

1,874 miData through Dec 2025Source: US DOT · BTS

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

On-time rate73%arrived within 15 min
p90 delay50 min1 in 10 flights is worse (tail risk)
Cancelled1.2%of scheduled flights

based on 2,113 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.

  • Alaska Airlines
    On-time72%
    Medianon time
    p9045 min
    Cancel1.9%
    Flights857
  • United Airlines
    On-time73%
    Medianon time
    p9050 min
    Cancel0.8%
    Flights1,256

Why flights run late

Delay causes

  • Airline31%
  • Weather4%
  • Air traffic (NAS)23%
  • Late aircraft42%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly IAH → SEA

All airlines · rolling 36 months (2023-01 .. 2025-12).

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 · 2,445 flights
  • Afternoons78% on time · p90 50 min · 779 flights
  • Middays78% on time · p90 50 min · 491 flights
  • Evenings67% on time · p90 60 min · 2,076 flights
  • Overnights57% on time · p90 75 min · 467 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 72% to 79% on time.

  • Tuesdays79% on time · p90 30 min · 883 flights
  • Saturdays77% on time · p90 40 min · 888 flights
  • Wednesdays77% on time · p90 35 min · 880 flights
  • Thursdays74% on time · p90 50 min · 903 flights
  • Fridays73% on time · p90 50 min · 908 flights
  • Mondays73% on time · p90 55 min · 912 flights
  • Sundays72% on time · p90 50 min · 884 flights
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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.