Historical on-time performance
Ontario to Chicago
1,706 miData through Dec 2025Source: US DOT · BTS
Flights on ONT–MDW arrive on time 92% of the time over the last 12 months.
On-time rate92%arrived within 15 min
p90 delay5 min1 in 10 flights is worse (tail risk)
Cancelled0.3%of scheduled flights
based on 306 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Southwest AirlinesOn-time92%Medianon timep905 minCancel0.3%Flights306
Why flights run late
Delay causes
- Airline53%
- Weather0%
- Air traffic (NAS)20%
- Late aircraft27%
- 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 ONT → MDW
All airlines · rolling 36 months (2023-01 .. 2025-12).
Best time of day
Mornings are the most reliable time of day to fly this route — 91% on time.
- Mornings91% on time · p90 10 min · 655 flights
- Middays84% on time · p90 15 min · 418 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 84% to 90% on time.
- Fridays90% on time · p90 10 min · 156 flights · limited
- Thursdays90% on time · p90 10 min · 156 flights · limited
- Sundays90% on time · p90 10 min · 165 flights · limited
- Saturdays89% on time · p90 10 min · 133 flights · limited
- Mondays87% on time · p90 20 min · 158 flights · limited
- Wednesdays87% on time · p90 15 min · 157 flights · limited
- Tuesdays84% on time · p90 15 min · 158 flights · limited
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