OnTimeStats

Historical on-time performance

Chicago to Waterloo

234 miData through May 2026Source: US DOT · BTS

Flights on ORD–ALO arrive on time 70% of the time over the last 12 months.

On-time rate70%arrived within 15 min
p90 delay65 min1 in 10 flights is worse (tail risk)
Cancelled2.4%of scheduled flights

based on 664 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Envoy Air
    On-time70%
    Medianon time
    p9065 min
    Cancel2.4%
    Flights664

Why flights run late

Delay causes

  • Airline12%
  • Weather18%
  • Air traffic (NAS)21%
  • Late aircraft49%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather81%
  • Air traffic (NAS)19%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 16 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 → ALO

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

Best time of day

Middays are the most reliable time of day to fly this route — 76% on time.

  • Middays76% on time · p90 50 min · 294 flights
  • Overnights64% on time · p90 80 min · 332 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 66% to 70% on time.

  • Sundays70% on time · p90 80 min · 104 flights · limited
  • Mondays70% on time · p90 80 min · 102 flights · limited
  • Fridays69% on time · p90 50 min · 103 flights · limited
  • Thursdays66% on time · p90 80 min · 101 flights · limited
  • Wednesdays66% on time · p90 90 min · 100 flights · limited

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.