OnTimeStats

Historical on-time performance

Portland to Houston

1,825 miData through May 2026Source: US DOT · BTS

Flights on PDX–IAH arrive on time 84% of the time over the last 12 months.

On-time rate84%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled0.9%of scheduled flights

based on 1,129 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlinesbest
    On-time85%
    Medianon time
    p9020 min
    Cancel0.9%
    Flights885
  • Alaska Airlines
    On-time79%
    Medianon time
    p9025 min
    Cancel0.8%
    Flights244

Why flights run late

Delay causes

  • Airline29%
  • Weather1%
  • Air traffic (NAS)37%
  • Late aircraft33%
  • Security1%

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

When flights don't go

Why flights were cancelled

  • Airline40%
  • Weather60%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 10 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 PDX → IAH

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 — 92% on time.

  • Mornings92% on time · p90 5 min · 1,116 flights
  • Afternoons84% on time · p90 25 min · 125 flights · limited
  • Overnights83% on time · p90 40 min · 458 flights
  • Middays79% on time · p90 30 min · 1,286 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 83% to 88% on time.

  • Saturdays88% on time · p90 15 min · 422 flights
  • Tuesdays88% on time · p90 15 min · 423 flights
  • Mondays84% on time · p90 25 min · 426 flights
  • Fridays84% on time · p90 30 min · 433 flights
  • Wednesdays84% on time · p90 20 min · 420 flights
  • Sundays83% on time · p90 25 min · 431 flights
  • Thursdays83% on time · p90 20 min · 430 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.