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Airport Reliability

ONT · Ontario

Ontario International Airport

82%
Departures within 15 minutes
10 min
Average departure delay
79%
Arrivals within 15 minutes
0.9%
Departures cancelled

Based on 26,642 departures and 26,639 arrivals. Data through May 2026.

What the data says

Morning-you made the right choice.

Departures from ONT departing between 3–6 AM arrived on time 95% of the time, versus 72% between 6–9 PM.

Saturday has been the better bet.

A small edge: 86% on time on Saturdays against 81% on Fridays.

Slipping a little lately.

Departures from ONT arrived on time 83% of the time over the last three months in the data, compared with 86% in the three months before that.

When ONT gets messy

On-time by departure window
  • 12–3 AM80%(157 flights)
  • 3–6 AM95%(1470 flights)
  • 6–9 AM91%(6860 flights)
  • 9 AM–12 PM86%(4336 flights)
  • 12–3 PM78%(4706 flights)
  • 3–6 PM78%(3930 flights)
  • 6–9 PM72%(3064 flights)
  • 9 PM–12 AM80%(1822 flights)
On-time by weekday
  • Mon82%(4039 flights)
  • Tue86%(3610 flights)
  • Wed86%(3547 flights)
  • Thu82%(3952 flights)
  • Fri81%(4004 flights)
  • Sat86%(3170 flights)
  • Sun82%(4023 flights)
On-time trend by month
81%
May

Jun 80% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202580%2365
July 202580%2448
August 202583%2331
September 202586%2193
October 202582%2303
November 202583%2164
December 202583%2146
January 202687%1914
February 202689%1780
March 202684%2127
April 202684%2192
May 202681%2382

Airlines departing ONT

Busiest routes from ONT

Based on 26,642 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.