OnTimeStats

Historical on-time performance

Seattle to Washington

2,329 miData through May 2026Source: US DOT · BTS

Flights on SEA–DCA arrive on time 77% of the time over the last 12 months.

On-time rate77%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled1.6%of scheduled flights

based on 1,066 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Delta Air Linesbest
    On-time88%
    Medianon time
    p9010 min
    Cancel2.7%
    Flights337
  • Alaska Airlines
    On-time72%
    Medianon time
    p9050 min
    Cancel1.1%
    Flights729

Why flights run late

Delay causes

  • Airline37%
  • Weather8%
  • Air traffic (NAS)45%
  • Late aircraft11%
  • Security0%

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

When flights don't go

Why flights were cancelled

  • Airline35%
  • Weather59%
  • Air traffic (NAS)6%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 17 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 → DCA

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 — 82% on time.

  • Mornings82% on time · p90 25 min · 1,545 flights
  • Afternoons74% on time · p90 40 min · 412 flights
  • Middays69% on time · p90 50 min · 681 flights

Best day of week

Saturdays are the most reliable day to fly this route — 87% on time.

  • Saturdays87% on time · p90 15 min · 378 flights
  • Wednesdays80% on time · p90 30 min · 376 flights
  • Tuesdays80% on time · p90 30 min · 376 flights
  • Fridays75% on time · p90 40 min · 378 flights
  • Sundays75% on time · p90 45 min · 379 flights
  • Thursdays73% on time · p90 50 min · 375 flights
  • Mondays72% on time · p90 40 min · 376 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.