OnTimeStats

Historical on-time performance

Chicago to Decatur

156 miData through Dec 2025Source: US DOT · BTS

Flights on ORD–DEC arrive on time 76% of the time over the last 12 months.

On-time rate76%arrived within 15 min
p90 delay65 min1 in 10 flights is worse (tail risk)
Cancelled1.8%of scheduled flights

based on 627 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • SkyWest Airlines
    On-time76%
    Medianon time
    p9065 min
    Cancel1.8%
    Flights627

Why flights run late

Delay causes

  • Airline35%
  • Weather10%
  • Air traffic (NAS)24%
  • Late aircraft30%
  • Security0%

Most delay minutes here are attributed to Airline.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly ORD → DEC

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

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 61% to 79% on time.

  • Middays79% on time · p90 50 min · 457 flights
  • Mornings78% on time · p90 40 min · 496 flights
  • Afternoons74% on time · p90 60 min · 861 flights
  • Evenings61% on time · p90 70 min · 61 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 71% to 79% on time.

  • Tuesdays79% on time · p90 50 min · 160 flights · limited
  • Mondays78% on time · p90 35 min · 312 flights
  • Saturdays77% on time · p90 60 min · 159 flights · limited
  • Thursdays77% on time · p90 55 min · 308 flights
  • Wednesdays76% on time · p90 65 min · 313 flights
  • Fridays75% on time · p90 45 min · 311 flights
  • Sundays71% on time · p90 70 min · 312 flights
Advertisement

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.