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Route Reliability

Denver → Ontario

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

82
Pretty Reliable
WanderNerd Reliability Score
75%
Arrive within 15 minutes
10 min
Average arrival delay
0.3%
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.Frontier Airlines80%546 flights
  2. 2.United Airlines78%867 flights
  3. 3.Southwest Airlines71%1,269 flights

What the data says

Morning-you made the right choice.

DEN–ONT flights departing between 6–9 AM arrived on time 90% of the time, versus 64% between 9 PM–12 AM.

Skip Monday if you can.

DEN–ONT flights arrived on time 81% of the time on Wednesdays. On Mondays: 69%.

Frontier Airlines runs this route best.

Frontier Airlines arrived on time 80% of the time on this route; Southwest Airlines managed 71%.

It basically never cancels.

Out of 2,682 scheduled flights, only 0.3% were cancelled.

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
  • Mon69%(407 flights)
  • Tue77%(348 flights)
  • Wed81%(354 flights)
  • Thu72%(408 flights)
  • Fri76%(406 flights)
  • Sat79%(336 flights)
  • Sun74%(415 flights)
On-time by departure window
  • 6–9 AM90%(501 flights)
  • 9 AM–12 PM87%(466 flights)
  • 12–3 PM75%(271 flights)
  • 3–6 PM71%(202 flights)
  • 6–9 PM66%(725 flights)
  • 9 PM–12 AM64%(509 flights)
On-time trend by month
76%
May

Jun 60% → May 76% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202560%257
July 202560%270
August 202573%254
September 202576%236
October 202576%241
November 202585%219
December 202571%194
January 202683%185
February 202683%171
March 202684%200
April 202685%205
May 202676%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.