Flight Reliability
DL 657 · Delta Air Lines
Salt Lake City → Boston (SLC–BOS)
86
Pretty Reliable
WanderNerd Reliability Score
- 83%
- Arrive within 15 minutes
- 1 min early
- Average arrival delay
- 1.1%
- Cancelled
- 8 min early
- Median arrival delay
Based on 365 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
DL 657 arrived on time 89% of the time on Saturdays. On Fridays: 79%.
The breakdown
- Mon84%(50 flights)
- Tue82%(51 flights)
- Wed83%(52 flights)
- Thu83%(52 flights)
- Fri79%(52 flights)
- Sat89%(52 flights)
- Sun81%(52 flights)
94%
May
Jun 87% → May 94% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 87% | 30 |
| July 2025 | 90% | 31 |
| August 2025 | 90% | 31 |
| September 2025 | 60% | 30 |
| October 2025 | 58% | 31 |
| November 2025 | 90% | 30 |
| December 2025 | 77% | 31 |
| January 2026 | 86% | 28 |
| February 2026 | 93% | 27 |
| March 2026 | 87% | 31 |
| April 2026 | 83% | 30 |
| May 2026 | 94% | 31 |
- Departures on time
- 82%
- Diverted
- 0%
- Flights flown
- 361
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 365 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.