OnTimeStats

Historical on-time performance

Atlanta to Chicago

606 miData through May 2026Source: US DOT · BTS

Flights on ATL–ORD arrive on time 68% of the time over the last 12 months.

On-time rate68%arrived within 15 min
p90 delay65 min1 in 10 flights is worse (tail risk)
Cancelled2.2%of scheduled flights

based on 6,025 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

  • Spirit Airlines
    On-time90%
    Medianon time
    p9010 min
    Cancel0.0%
    Flights30
  • United Airlines
    On-time74%
    Medianon time
    p9050 min
    Cancel1.4%
    Flights1,575
  • Envoy Air
    On-time72%
    Medianon time
    p9060 min
    Cancel2.8%
    Flights288
  • American Airlines
    On-time68%
    Medianon time
    p9095 min
    Cancel2.6%
    Flights627
  • Delta Air Lines
    On-time66%
    Medianon time
    p9055 min
    Cancel2.1%
    Flights2,622
  • Republic Airways
    On-time66%
    Medianon time
    p9065 min
    Cancel5.1%
    Flights177
  • Frontier Airlines
    On-time59%
    Medianon time
    p90105 min
    Cancel3.0%
    Flights706

Why flights run late

Delay causes

  • Airline29%
  • Weather8%
  • Air traffic (NAS)34%
  • Late aircraft30%
  • Security0%

Most delay minutes here are attributed to Air traffic (NAS).

When flights don't go

Why flights were cancelled

  • Airline42%
  • Weather47%
  • Air traffic (NAS)11%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 132 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 ATL → ORD

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Mornings are the most reliable time of day to fly this route — 82% on time.

  • Mornings82% on time · p90 25 min · 4,743 flights
  • Middays80% on time · p90 35 min · 4,588 flights
  • Afternoons69% on time · p90 65 min · 2,866 flights
  • Overnights65% on time · p90 80 min · 2,157 flights
  • Evenings59% on time · p90 85 min · 3,581 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 70% to 78% on time.

  • Wednesdays78% on time · p90 40 min · 2,527 flights
  • Tuesdays76% on time · p90 45 min · 2,460 flights
  • Saturdays74% on time · p90 50 min · 2,275 flights
  • Mondays72% on time · p90 60 min · 2,680 flights
  • Thursdays71% on time · p90 50 min · 2,668 flights
  • Fridays70% on time · p90 55 min · 2,708 flights
  • Sundays70% on time · p90 65 min · 2,617 flights

Keep exploring

Related pages

Delay predictorfor this route→ATL airportAtlanta→ORD airportChicago→Delta Air Linesairline profile→United Airlinesairline profile→Frontier Airlinesairline profile→Seasonal delay patternsguide→

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.