OnTimeStats

Historical on-time performance

Washington to Portland

2,327 miData through May 2026Source: US DOT · BTS

Flights on IAD–PDX arrive on time 75% of the time over the last 12 months.

On-time rate75%arrived within 15 min
p90 delay65 min1 in 10 flights is worse (tail risk)
Cancelled0.0%of scheduled flights

based on 244 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlines
    On-time75%
    Medianon time
    p9065 min
    Cancel0.0%
    Flights244

Why flights run late

Delay causes

  • Airline29%
  • Weather25%
  • Air traffic (NAS)25%
  • Late aircraft20%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline56%
  • Weather33%
  • Air traffic (NAS)11%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 9 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 IAD → PDX

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

Best day of week

On-time rates are fairly even by day on this route — ranging from 65% to 82% on time.

  • Sundays82% on time · p90 60 min · 127 flights · limited
  • Fridays81% on time · p90 70 min · 130 flights · limited
  • Wednesdays78% on time · p90 55 min · 125 flights · limited
  • Tuesdays78% on time · p90 35 min · 125 flights · limited
  • Mondays76% on time · p90 55 min · 118 flights · limited
  • Saturdays74% on time · p90 80 min · 130 flights · limited
  • Thursdays65% on time · p90 55 min · 121 flights · limited

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.