Flight Reliability
AS 639 · Alaska Airlines
Seattle → Tampa (SEA–TPA)99% of its flights flew this route. The rest (PSC–SEA) are included in these numbers.
93
Nerd Approved
WanderNerd Reliability Score
- 85%
- Arrive within 15 minutes
- 1 min early
- Average arrival delay
- 0%
- Cancelled
- 6 min early
- Median arrival delay
Based on 144 historical flights. Data through May 2026.
What the data says
Tuesday has been the better bet.
A small edge: 89% on time on Tuesdays against 83% on Sundays.
Better than the SEA–TPA route average.
AS 639 arrived on time 85% of the time, versus 77% across the SEA–TPA route.
A bit ahead of the Alaska Airlines network.
AS 639 arrived on time 85% of the time, versus 80% across the Alaska Airlines network.
It basically never cancels.
Out of 144 scheduled flights, only 0.0% were cancelled.
The breakdown
- Mon86%(22 flights)
- Tue89%(18 flights)
- Wed83%(18 flights)
- Thu86%(21 flights)
- Fri83%(23 flights)
- Sat84%(19 flights)
- Sun83%(23 flights)
- 6–9 AM—(1 flights)
- 9 PM–12 AM85%(143 flights)
73%
May
Dec 88% → May 73% on time
| Month | On-time percentage | Flights |
|---|---|---|
| December 2025 | 88% | 25 |
| February 2026 | 94% | 17 |
| March 2026 | 90% | 29 |
| April 2026 | 89% | 27 |
| May 2026 | 73% | 30 |
- Departures on time
- 76%
- Diverted
- 0%
- Flights flown
- 144
- Months covered
- 8
Same route, other flights
Keep nerding
Based on 144 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.