OnTimeStats

Historical on-time performance

Chicago to Boise

1,437 miData through May 2026Source: US DOT · BTS

Flights on ORD–BOI arrive on time 67% of the time over the last 12 months.

On-time rate67%arrived within 15 min
p90 delay80 min1 in 10 flights is worse (tail risk)
Cancelled1.3%of scheduled flights

based on 870 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • American Airlines
    On-time82%
    Medianon time
    p9030 min
    Cancel0.0%
    Flights91
  • United Airlinesbest
    On-time79%
    Medianon time
    p9040 min
    Cancel0.0%
    Flights214
  • Envoy Air
    On-time65%
    Medianon time
    p9045 min
    Cancel0.0%
    Flights92
  • SkyWest Airlines
    On-time59%
    Medianon time
    p90100 min
    Cancel2.3%
    Flights473

Why flights run late

Delay causes

  • Airline40%
  • Weather6%
  • Air traffic (NAS)21%
  • Late aircraft33%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline9%
  • Weather82%
  • Air traffic (NAS)9%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 11 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 → BOI

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 — 80% on time.

  • Mornings80% on time · p90 35 min · 1,382 flights
  • Evenings60% on time · p90 85 min · 697 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 69% to 78% on time.

  • Saturdays78% on time · p90 35 min · 317 flights
  • Thursdays75% on time · p90 55 min · 319 flights
  • Tuesdays73% on time · p90 55 min · 311 flights
  • Wednesdays72% on time · p90 65 min · 319 flights
  • Sundays70% on time · p90 75 min · 321 flights
  • Mondays69% on time · p90 55 min · 312 flights
  • Fridays69% on time · p90 65 min · 321 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.