OnTimeStats

Historical on-time performance

Houston to Washington

1,190 miData through May 2026Source: US DOT · BTS

Flights on IAH–IAD arrive on time 79% of the time over the last 12 months.

On-time rate79%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled0.6%of scheduled flights

based on 1,862 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlines
    On-time79%
    Medianon time
    p9040 min
    Cancel0.6%
    Flights1,862

Why flights run late

Delay causes

  • Airline31%
  • Weather12%
  • Air traffic (NAS)22%
  • Late aircraft35%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather100%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 11 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 IAH → IAD

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 — 91% on time.

  • Mornings91% on time · p90 10 min · 1,131 flights
  • Overnights78% on time · p90 45 min · 102 flights · limited
  • Afternoons76% on time · p90 45 min · 1,026 flights
  • Middays72% on time · p90 40 min · 1,185 flights
  • Evenings72% on time · p90 55 min · 1,876 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 74% to 80% on time.

  • Tuesdays80% on time · p90 40 min · 745 flights
  • Wednesdays78% on time · p90 40 min · 751 flights
  • Thursdays77% on time · p90 35 min · 764 flights
  • Mondays77% on time · p90 40 min · 755 flights
  • Sundays76% on time · p90 40 min · 763 flights
  • Saturdays75% on time · p90 45 min · 766 flights
  • Fridays74% on time · p90 45 min · 776 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.