Flight Reliability
F9 4987 · Frontier Airlines
Salt Lake City → Seattle (SLC–SEA)
66
Usually Fine
WanderNerd Reliability Score
- 70%
- Arrive within 15 minutes
- 12 min
- Average arrival delay
- 2.8%
- Cancelled
- 4 min early
- Median arrival delay
Based on 107 historical flights. Data through May 2026.
What the data says
The late departure is the smart one here.
F9 4987 departing between 6–9 PM arrived on time 94% of the time, versus 64% between 3–6 PM.
Sunday scaries are real for this one.
F9 4987 arrived on time 75% of the time on Fridays and just 60% on Sundays. That gap is worth planning around.
Lagging the SLC–SEA route.
F9 4987 arrived on time 70% of the time, versus 80% across the SLC–SEA route.
The breakdown
- Mon74%(39 flights)
- Tue—(3 flights)
- Wed—(0 flights)
- Thu—(2 flights)
- Fri75%(40 flights)
- Sat—(5 flights)
- Sun60%(15 flights)
- 9 AM–12 PM67%(15 flights)
- 12–3 PM66%(58 flights)
- 3–6 PM64%(14 flights)
- 6–9 PM94%(17 flights)
43%
Dec
Aug 83% → Dec 43% on time
| Month | On-time percentage | Flights |
|---|---|---|
| August 2025 | 83% | 12 |
| September 2025 | 69% | 13 |
| October 2025 | 58% | 12 |
| November 2025 | 54% | 13 |
| December 2025 | 43% | 14 |
- Departures on time
- 82%
- Diverted
- 0%
- Flights flown
- 104
- Months covered
- 11
Same route, other flights
Keep nerding
Based on 107 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.