OnTimeStats

Historical on-time performance

Chicago to Salt Lake City

1,258 miData through May 2026Source: US DOT · BTS

Flights on MDW–SLC arrive on time 69% of the time over the last 12 months.

On-time rate69%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled1.9%of scheduled flights

based on 617 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time69%
    Medianon time
    p9040 min
    Cancel1.9%
    Flights617

Why flights run late

Delay causes

  • Airline31%
  • Weather3%
  • Air traffic (NAS)19%
  • Late aircraft47%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline25%
  • Weather67%
  • Air traffic (NAS)8%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 12 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 MDW → SLC

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 65% to 85% on time.

  • Mornings85% on time · p90 20 min · 633 flights
  • Middays81% on time · p90 25 min · 420 flights
  • Evenings74% on time · p90 40 min · 113 flights · limited
  • Overnights65% on time · p90 60 min · 696 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 73% to 79% on time.

  • Saturdays79% on time · p90 30 min · 215 flights
  • Tuesdays78% on time · p90 35 min · 290 flights
  • Mondays78% on time · p90 30 min · 298 flights
  • Wednesdays76% on time · p90 35 min · 287 flights
  • Thursdays76% on time · p90 40 min · 297 flights
  • Sundays73% on time · p90 45 min · 273 flights
  • Fridays73% on time · p90 35 min · 301 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.