OnTimeStats

Historical on-time performance

Seattle to Salt Lake City

689 miData through Dec 2025Source: US DOT · BTS

Flights on SEA–SLC arrive on time 82% of the time over the last 12 months.

On-time rate82%arrived within 15 min
Median delayon timetypical arrival
p90 delay25 min1 in 10 flights is worsetail risk
Cancelled0.7%of scheduled flights

based on 3,952 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
    p9015 min
    Cancel0.3%
    Flights2,219
  • Alaska Airlines
    On-time74%
    Medianon time
    p9035 min
    Cancel1.8%
    Flights1,253
  • SkyWest Airlines
    On-time80%
    Medianon time
    p9030 min
    Cancel0.0%
    Flights480

Why flights run late

Delay causes

  • Airline46%
  • Weather3%
  • Air traffic (NAS)13%
  • Late aircraft39%
  • Security0%

Most delay minutes here are attributed to Airline.

Over time

On-time trend

By season

On-time rate by month

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Keep exploring

Related pages

Delay predictorfor this route→SEA airportSeattle→SLC airportSalt Lake City→Delta Air Lines on this routecarrier detail→Delta Air Linesairline profile→

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.