OnTimeStats

Historical on-time performance

Chicago to Los Angeles

1,745 miData through May 2026Source: US DOT · BTS

Flights on ORD–LAX arrive on time 73% of the time over the last 12 months.

On-time rate73%arrived within 15 min
p90 delay55 min1 in 10 flights is worse (tail risk)
Cancelled1.4%of scheduled flights

based on 6,773 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.

  • United Airlines
    On-time77%
    Medianon time
    p9045 min
    Cancel0.6%
    Flights3,396
  • Spirit Airlines
    On-time75%
    Medianon time
    p9065 min
    Cancel2.5%
    Flights276
  • American Airlines
    On-time68%
    Medianon time
    p9065 min
    Cancel2.2%
    Flights3,040
  • Frontier Airlines
    On-time62%
    Median5 min
    p9095 min
    Cancel3.3%
    Flights61

Why flights run late

Delay causes

  • Airline34%
  • Weather8%
  • Air traffic (NAS)16%
  • Late aircraft42%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline30%
  • Weather58%
  • Air traffic (NAS)11%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 96 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 ORD → LAX

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 — 83% on time.

  • Mornings83% on time · p90 25 min · 5,998 flights
  • Middays81% on time · p90 35 min · 4,034 flights
  • Afternoons76% on time · p90 50 min · 3,476 flights
  • Evenings67% on time · p90 70 min · 3,763 flights
  • Overnights64% on time · p90 65 min · 3,072 flights

Best day of week

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

  • Wednesdays79% on time · p90 45 min · 2,825 flights
  • Tuesdays78% on time · p90 40 min · 2,771 flights
  • Thursdays76% on time · p90 45 min · 3,015 flights
  • Saturdays76% on time · p90 45 min · 2,703 flights
  • Mondays76% on time · p90 55 min · 2,989 flights
  • Fridays74% on time · p90 50 min · 3,032 flights
  • Sundays73% on time · p90 50 min · 3,010 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.