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Route Reliability

Ontario → Denver

ONT–DEN · 819 miles · Ontario International Airport to Denver International Airport

83
Pretty Reliable
WanderNerd Reliability Score
79%
Arrive within 15 minutes
8 min
Average arrival delay
0.6%
Cancelled
2,682
Flights in the data

Data through May 2026.

Who flies it best

Ranked by on-time arrivals. Historical results, not predictions.

  1. 1.United Airlines84%867 flights
  2. 2.Frontier Airlines77%546 flights
  3. 3.Southwest Airlines77%1,269 flights

What the data says

Morning-you made the right choice.

ONT–DEN flights departing between 3–6 AM arrived on time 94% of the time, versus 51% between 3–6 PM.

Skip Thursday if you can.

ONT–DEN flights arrived on time 84% of the time on Saturdays. On Thursdays: 77%.

United Airlines has a slight edge here.

United Airlines arrived on time 84% of the time on this route; Southwest Airlines managed 77%.

Best historical flights

Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.

Top flights by on-time rate

More flights on this route

The breakdown

On-time by weekday
  • Mon79%(406 flights)
  • Tue78%(349 flights)
  • Wed78%(354 flights)
  • Thu77%(403 flights)
  • Fri80%(400 flights)
  • Sat84%(337 flights)
  • Sun80%(408 flights)
On-time by departure window
  • 12–3 AM77%(123 flights)
  • 3–6 AM94%(562 flights)
  • 6–9 AM89%(514 flights)
  • 9 AM–12 PM84%(262 flights)
  • 12–3 PM73%(682 flights)
  • 3–6 PM51%(328 flights)
  • 6–9 PM76%(183 flights)
  • 9 PM–12 AM—(3 flights)
On-time trend by month
84%
May

Jun 67% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202567%254
July 202566%267
August 202574%251
September 202581%237
October 202587%239
November 202586%220
December 202577%194
January 202688%184
February 202687%169
March 202676%196
April 202686%204
May 202684%242

Same trip, other airports

Keep nerding

Based on 2,682 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.