Flight Reliability
F9 3981 · Frontier Airlines
Denver → Salt Lake City (DEN–SLC)
84
Pretty Reliable
WanderNerd Reliability Score
- 79%
- Arrive within 15 minutes
- 9 min
- Average arrival delay
- 0.8%
- Cancelled
- 12 min early
- Median arrival delay
Based on 123 historical flights. Data through May 2026.
What the data says
The late departure is the smart one here.
F9 3981 departing between 6–9 PM arrived on time 88% of the time, versus 63% between 3–6 PM.
Wednesday has been the better bet.
A small edge: 83% on time on Wednesdays against 79% on Saturdays.
A bit ahead of the Frontier Airlines network.
F9 3981 arrived on time 79% of the time, versus 73% across the Frontier Airlines network.
The breakdown
- Mon—(3 flights)
- Tue80%(44 flights)
- Wed83%(30 flights)
- Thu—(3 flights)
- Fri—(4 flights)
- Sat79%(34 flights)
- Sun—(4 flights)
- 12–3 PM80%(10 flights)
- 3–6 PM63%(16 flights)
- 6–9 PM88%(49 flights)
- 9 PM–12 AM75%(47 flights)
70%
May
Aug 73% → May 70% on time
| Month | On-time percentage | Flights |
|---|---|---|
| August 2025 | 73% | 11 |
| September 2025 | 92% | 13 |
| October 2025 | 92% | 13 |
| January 2026 | 90% | 10 |
| May 2026 | 70% | 27 |
- Departures on time
- 80%
- Diverted
- 0%
- Flights flown
- 122
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 123 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.