OnTimeStats

Historical on-time performance

Chicago to San Francisco

1,855 miData through Dec 2025Source: US DOT · BTS

Flights on MDW–SFO arrive on time 68% of the time over the last 12 months.

On-time rate68%arrived within 15 min
p90 delay40 min1 in 10 flights is worse (tail risk)
Cancelled0.7%of scheduled flights

based on 275 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time68%
    Medianon time
    p9040 min
    Cancel0.7%
    Flights275

Why flights run late

Delay causes

  • Airline35%
  • Weather3%
  • Air traffic (NAS)27%
  • Late aircraft35%
  • 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 MDW → SFO

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 — 74% on time.

  • Mornings74% on time · p90 45 min · 231 flights
  • Evenings62% on time · p90 60 min · 122 flights · limited
  • Middays61% on time · p90 55 min · 274 flights
  • Afternoons54% on time · p90 120 min · 238 flights
  • Overnights47% on time · p90 95 min · 90 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 54% to 66% on time.

  • Tuesdays66% on time · p90 75 min · 122 flights · limited
  • Sundays66% on time · p90 80 min · 122 flights · limited
  • Mondays64% on time · p90 60 min · 151 flights · limited
  • Saturdays61% on time · p90 70 min · 140 flights · limited
  • Wednesdays59% on time · p90 65 min · 134 flights · limited
  • Thursdays59% on time · p90 75 min · 135 flights · limited
  • Fridays54% on time · p90 75 min · 151 flights · limited
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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.