Flight Reliability
AS 643 · Alaska Airlines
Denver → Seattle (DEN–SEA)
97
Nerd Approved
WanderNerd Reliability Score
- 89%
- Arrive within 15 minutes
- 1 min early
- Average arrival delay
- 0%
- Cancelled
- 11 min early
- Median arrival delay
Based on 295 historical flights. Data through May 2026.
What the data says
Thursday is the weak spot.
AS 643 arrived on time 95% of the time on Fridays. On Thursdays: 83%.
Better than the DEN–SEA route average.
AS 643 arrived on time 89% of the time, versus 74% across the DEN–SEA route.
Better than the Alaska Airlines network average.
AS 643 arrived on time 89% of the time, versus 80% across the Alaska Airlines network.
It basically never cancels.
Out of 295 scheduled flights, only 0.0% were cancelled.
The breakdown
- Mon88%(43 flights)
- Tue93%(43 flights)
- Wed88%(42 flights)
- Thu83%(42 flights)
- Fri95%(41 flights)
- Sat88%(40 flights)
- Sun84%(44 flights)
90%
May
Jun 83% → May 90% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 83% | 30 |
| July 2025 | 84% | 31 |
| August 2025 | 90% | 19 |
| November 2025 | 90% | 29 |
| December 2025 | 72% | 29 |
| January 2026 | 94% | 31 |
| February 2026 | 93% | 28 |
| March 2026 | 87% | 31 |
| April 2026 | 100% | 30 |
| May 2026 | 90% | 31 |
- Departures on time
- 92%
- Diverted
- 0%
- Flights flown
- 295
- Months covered
- 11
Same route, other flights
Keep nerding
Based on 295 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.