Flight Reliability
DL 3557 · Delta Air Lines
Seattle → San Jose (SEA–SJC)99% of its flights flew this route. The rest (ATL–LFT) are included in these numbers.
98
Nerd Approved
WanderNerd Reliability Score
- 92%
- Arrive within 15 minutes
- 5 min early
- Average arrival delay
- 0.5%
- Cancelled
- 14 min early
- Median arrival delay
Based on 185 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
DL 3557 arrived on time 96% of the time on Wednesdays and just 81% on Fridays. That gap is worth planning around.
Better than the SEA–SJC route average.
DL 3557 arrived on time 92% of the time, versus 82% across the SEA–SJC route.
Better than the Delta Air Lines network average.
DL 3557 arrived on time 92% of the time, versus 81% across the Delta Air Lines network.
The breakdown
- Mon93%(28 flights)
- Tue96%(25 flights)
- Wed96%(26 flights)
- Thu92%(26 flights)
- Fri81%(26 flights)
- Sat92%(25 flights)
- Sun93%(28 flights)
- 6–9 PM92%(183 flights)
- 9 PM–12 AM—(1 flights)
95%
Dec
Jun 83% → Dec 95% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 83% | 24 |
| July 2025 | 94% | 31 |
| August 2025 | 90% | 29 |
| September 2025 | 100% | 23 |
| October 2025 | 84% | 31 |
| November 2025 | 100% | 27 |
| December 2025 | 95% | 19 |
- Departures on time
- 92%
- Diverted
- 0%
- Flights flown
- 184
- Months covered
- 7
Same route, other flights
Keep nerding
Based on 185 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.