OnTimeStats

Historical on-time performance

Washington to San Francisco

2,419 miData through May 2026Source: US DOT · BTS

Flights on IAD–SFO arrive on time 78% of the time over the last 12 months.

On-time rate78%arrived within 15 min
p90 delay50 min1 in 10 flights is worse (tail risk)
Cancelled0.8%of scheduled flights

based on 2,828 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Not enough comparable data to name a most-on-time carrier — low-data carriers aren't ranked.

  • United Airlines
    On-time79%
    Medianon time
    p9045 min
    Cancel0.9%
    Flights2,669
  • Alaska Airlines
    On-time66%
    Medianon time
    p9075 min
    Cancel0.6%
    Flights159

Why flights run late

Delay causes

  • Airline32%
  • Weather6%
  • Air traffic (NAS)31%
  • Late aircraft30%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline54%
  • Weather46%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 24 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 → SFO

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

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 64% to 84% on time.

  • Mornings84% on time · p90 20 min · 2,749 flights
  • Middays83% on time · p90 30 min · 1,099 flights
  • Overnights81% on time · p90 35 min · 1,122 flights
  • Afternoons80% on time · p90 40 min · 1,337 flights
  • Evenings64% on time · p90 75 min · 1,968 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 76% to 82% on time.

  • Tuesdays82% on time · p90 35 min · 1,128 flights
  • Wednesdays80% on time · p90 40 min · 1,142 flights
  • Saturdays78% on time · p90 40 min · 1,146 flights
  • Thursdays77% on time · p90 40 min · 1,212 flights
  • Mondays77% on time · p90 45 min · 1,212 flights
  • Sundays77% on time · p90 45 min · 1,218 flights
  • Fridays76% on time · p90 45 min · 1,217 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.