OnTimeStats

Historical on-time performance

St. Louis to Salt Lake City

1,156 miData through Dec 2025Source: US DOT · BTS

Flights on STL–SLC arrive on time 88% of the time over the last 12 months.

On-time rate88%arrived within 15 min
p90 delay15 min1 in 10 flights is worse (tail risk)
Cancelled0.8%of scheduled flights

based on 964 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Delta Air Lines
    On-time88%
    Medianon time
    p9015 min
    Cancel0.8%
    Flights964

Why flights run late

Delay causes

  • Airline33%
  • Weather20%
  • Air traffic (NAS)10%
  • Late aircraft37%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly STL → SLC

All airlines · rolling 36 months (2023-01 .. 2025-12).

Best time of day

Mornings are the most reliable time of day to fly this route — 93% on time.

  • Mornings93% on time · p90 5 min · 1,094 flights
  • Afternoons88% on time · p90 15 min · 832 flights
  • Evenings85% on time · p90 20 min · 928 flights
  • Middays77% on time · p90 35 min · 74 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 87% to 91% on time.

  • Tuesdays91% on time · p90 10 min · 404 flights
  • Wednesdays90% on time · p90 10 min · 407 flights
  • Thursdays89% on time · p90 10 min · 434 flights
  • Saturdays89% on time · p90 15 min · 374 flights
  • Mondays88% on time · p90 15 min · 445 flights
  • Fridays87% on time · p90 20 min · 435 flights
  • Sundays87% on time · p90 20 min · 445 flights
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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.