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Flight Reliability

F9 1261 · Frontier Airlines

Denver → Ontario (DEN–ONT)

95
Nerd Approved
WanderNerd Reliability Score
87%
Arrive within 15 minutes
1 min
Average arrival delay
0%
Cancelled
10 min early
Median arrival delay

Based on 264 historical flights. Data through May 2026.

What the data says

The 12–3 PM departure wins.

F9 1261 departing between 12–3 PM arrived on time 100% of the time, versus 82% between 9 PM–12 AM.

Monday is the weak spot.

F9 1261 arrived on time 92% of the time on Fridays. On Mondays: 78%.

Better than the DEN–ONT route average.

F9 1261 arrived on time 87% of the time, versus 75% across the DEN–ONT route.

Better than the Frontier Airlines network average.

F9 1261 arrived on time 87% of the time, versus 73% across the Frontier Airlines network.

The breakdown

On-time by weekday
  • Mon78%(41 flights)
  • Tue82%(33 flights)
  • Wed88%(33 flights)
  • Thu90%(40 flights)
  • Fri92%(39 flights)
  • Sat86%(36 flights)
  • Sun91%(42 flights)
On-time by departure window
  • 6–9 AM89%(117 flights)
  • 9 AM–12 PM92%(26 flights)
  • 12–3 PM100%(15 flights)
  • 3–6 PM—(2 flights)
  • 6–9 PM—(9 flights)
  • 9 PM–12 AM82%(95 flights)
On-time trend by month
74%
May

Jun 80% → May 74% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202580%30
July 202587%31
August 2025100%25
September 202594%17
October 202589%18
November 202591%22
December 2025100%11
January 202692%12
March 202679%28
April 202690%30
May 202674%31
Departures on time
84%
Diverted
0%
Flights flown
264
Months covered
12

Same route, other flights

Keep nerding

Based on 264 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.