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Flight Reliability

F9 4989 · Frontier Airlines

Denver → San Diego (DEN–SAN)

75
Usually Fine
WanderNerd Reliability Score
76%
Arrive within 15 minutes
3 min
Average arrival delay
1.6%
Cancelled
5 min early
Median arrival delay

Based on 186 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

F9 4989 departing between 9 PM–12 AM arrived on time 78% of the time, versus 66% between 6–9 PM.

Friday is doing you no favors.

F9 4989 arrived on time 84% of the time on Saturdays and just 68% on Fridays. That gap is worth planning around.

Trending in the right direction.

F9 4989 arrived on time 82% of the time over the last three months in the data, compared with 73% in the three months before that.

The breakdown

On-time by weekday
  • Mon78%(36 flights)
  • Tue—(9 flights)
  • Wed—(9 flights)
  • Thu79%(33 flights)
  • Fri68%(37 flights)
  • Sat84%(19 flights)
  • Sun69%(39 flights)
On-time by departure window
  • 3–6 PM—(1 flights)
  • 6–9 PM66%(38 flights)
  • 9 PM–12 AM78%(143 flights)
On-time trend by month
73%
May

Jun 46% → May 73% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202546%13
November 202592%12
December 202558%24
January 202675%16
February 202684%19
March 202686%29
April 202686%22
May 202673%22
Departures on time
72%
Diverted
0.5%
Flights flown
182
Months covered
12

Same route, other flights

Keep nerding

Based on 186 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.