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Flight Reliability

F9 4545 · Frontier Airlines

Denver → Seattle (DEN–SEA)

83
Pretty Reliable
WanderNerd Reliability Score
80%
Arrive within 15 minutes
2 min
Average arrival delay
1.2%
Cancelled
9 min early
Median arrival delay

Based on 164 historical flights. Data through May 2026.

What the data says

Morning flights do better here.

F9 4545 departing between 6–9 AM arrived on time 92% of the time, versus 65% between 9 PM–12 AM.

Tuesdays have been rough.

F9 4545 arrived on time 100% of the time on Thursdays and just 68% on Tuesdays. That gap is worth planning around.

A bit ahead of the DEN–SEA route.

F9 4545 arrived on time 80% of the time, versus 74% across the DEN–SEA route.

Better than the Frontier Airlines network average.

F9 4545 arrived on time 80% of the time, versus 73% across the Frontier Airlines network.

The breakdown

On-time by weekday
  • Mon73%(22 flights)
  • Tue68%(28 flights)
  • Wed88%(17 flights)
  • Thu100%(18 flights)
  • Fri73%(22 flights)
  • Sat81%(32 flights)
  • Sun87%(23 flights)
On-time by departure window
  • 3–6 AM—(9 flights)
  • 6–9 AM92%(48 flights)
  • 9 AM–12 PM77%(64 flights)
  • 6–9 PM76%(21 flights)
  • 9 PM–12 AM65%(20 flights)
On-time trend by month
87%
May

Aug 90% → May 87% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
August 202590%10
September 202569%13
October 202591%11
November 202590%10
December 202571%24
March 202673%15
April 202693%27
May 202687%31
Departures on time
77%
Diverted
0%
Flights flown
162
Months covered
11

Same route, other flights

Keep nerding

Based on 164 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.