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Route Reliability

Ontario → Chicago

ONT–ORD · 1,700 miles · Ontario International Airport to Chicago O'Hare International Airport

82
Pretty Reliable
WanderNerd Reliability Score
80%
Arrive within 15 minutes
11 min
Average arrival delay
0.7%
Cancelled
291
Flights in the data

Data through May 2026.

United Airlines is the only airline in this data on this route, arriving on time 80% of the time across 291 flights. No comparison to make.

What the data says

Departure time hasn't mattered much.

On-time rates stay between 79% and 80% across the day.

Sunday scaries are real for this one.

ONT–ORD flights arrived on time 90% of the time on Wednesdays and just 70% on Sundays. That gap is worth planning around.

Flights on this route

The breakdown

On-time by weekday
  • Mon88%(42 flights)
  • Tue74%(39 flights)
  • Wed90%(40 flights)
  • Thu76%(42 flights)
  • Fri82%(39 flights)
  • Sat81%(42 flights)
  • Sun70%(43 flights)
On-time by departure window
  • 6–9 AM80%(245 flights)
  • 9 PM–12 AM79%(42 flights)
On-time trend by month
77%
May

Jun 83% → May 77% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202583%30
July 202581%31
August 202583%30
September 202586%29
October 202574%31
November 202577%30
December 202580%15
March 202673%26
April 202683%29
May 202677%31

Same trip, other airports

Keep nerding

Based on 291 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.