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Flight Reliability

F9 1279 · Frontier Airlines

Miami → Denver (MIA–DEN)

86
Pretty Reliable
WanderNerd Reliability Score
85%
Arrive within 15 minutes
8 min
Average arrival delay
1.5%
Cancelled
11 min early
Median arrival delay

Based on 331 historical flights. Data through May 2026.

What the data says

Morning-you made the right choice.

F9 1279 departing between 6–9 AM arrived on time 90% of the time, versus 70% between 12–3 PM.

Sunday scaries are real for this one.

F9 1279 arrived on time 94% of the time on Fridays and just 76% on Sundays. That gap is worth planning around.

A bit ahead of the MIA–DEN route.

F9 1279 arrived on time 85% of the time, versus 79% across the MIA–DEN route.

Better than the Frontier Airlines network average.

F9 1279 arrived on time 85% of the time, versus 73% across the Frontier Airlines network.

The breakdown

On-time by weekday
  • Mon88%(51 flights)
  • Tue77%(34 flights)
  • Wed83%(35 flights)
  • Thu92%(52 flights)
  • Fri94%(51 flights)
  • Sat81%(52 flights)
  • Sun76%(50 flights)
On-time by departure window
  • 3–6 AM70%(37 flights)
  • 6–9 AM90%(257 flights)
  • 9 AM–12 PM—(5 flights)
  • 12–3 PM70%(10 flights)
  • 3–6 PM—(7 flights)
  • 6–9 PM—(9 flights)
On-time trend by month
81%
May

Jun 89% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202589%26
July 202597%29
August 202581%26
September 202595%21
October 202591%22
November 202596%23
December 202579%29
January 202677%30
February 202696%27
March 202665%31
April 202683%30
May 202681%31
Departures on time
83%
Diverted
0.3%
Flights flown
325
Months covered
12

Same route, other flights

Keep nerding

Based on 331 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.