Flight Reliability
AS 591 · Alaska Airlines
San Francisco → Seattle (SFO–SEA)
67
Usually Fine
WanderNerd Reliability Score
- 68%
- Arrive within 15 minutes
- 14 min
- Average arrival delay
- 1.3%
- Cancelled
- 4 min
- Median arrival delay
Based on 223 historical flights. Data through May 2026.
What the data says
The late departure is the smart one here.
AS 591 departing between 6–9 PM arrived on time 76% of the time, versus 67% between 3–6 PM.
Friday is doing you no favors.
AS 591 arrived on time 77% of the time on Tuesdays and just 59% on Fridays. That gap is worth planning around.
Lagging the SFO–SEA route.
AS 591 arrived on time 68% of the time, versus 75% across the SFO–SEA route.
Lagging the Alaska Airlines network.
AS 591 arrived on time 68% of the time, versus 80% across the Alaska Airlines network.
The breakdown
- Mon61%(36 flights)
- Tue77%(34 flights)
- Wed68%(31 flights)
- Thu65%(34 flights)
- Fri59%(29 flights)
- Sat73%(30 flights)
- Sun76%(25 flights)
- 3–6 PM67%(198 flights)
- 6–9 PM76%(21 flights)
75%
May
Jun 50% → May 75% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 50% | 16 |
| July 2025 | 39% | 26 |
| August 2025 | 53% | 15 |
| October 2025 | 79% | 24 |
| November 2025 | 62% | 26 |
| December 2025 | 71% | 24 |
| January 2026 | 72% | 25 |
| February 2026 | 89% | 27 |
| March 2026 | 87% | 15 |
| May 2026 | 75% | 12 |
- Departures on time
- 69%
- Diverted
- 0.4%
- Flights flown
- 219
- Months covered
- 11
Same route, other flights
Keep nerding
Based on 223 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.