Flight Reliability
DL 660 · Delta Air Lines
Atlanta → Salt Lake City (ATL–SLC)
79
Usually Fine
WanderNerd Reliability Score
- 74%
- Arrive within 15 minutes
- 9 min
- Average arrival delay
- 0.6%
- Cancelled
- 3 min early
- Median arrival delay
Based on 361 historical flights. Data through May 2026.
What the data says
Skip Wednesday if you can.
DL 660 arrived on time 81% of the time on Sundays. On Wednesdays: 67%.
Lagging the ATL–SLC route.
DL 660 arrived on time 74% of the time, versus 83% across the ATL–SLC route.
Lagging the Delta Air Lines network.
DL 660 arrived on time 74% of the time, versus 81% across the Delta Air Lines network.
The breakdown
- Mon71%(52 flights)
- Tue81%(52 flights)
- Wed67%(52 flights)
- Thu71%(51 flights)
- Fri71%(48 flights)
- Sat75%(51 flights)
- Sun81%(53 flights)
74%
May
Jun 38% → May 74% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 38% | 29 |
| July 2025 | 58% | 31 |
| August 2025 | 77% | 31 |
| September 2025 | 77% | 30 |
| October 2025 | 63% | 30 |
| November 2025 | 63% | 27 |
| December 2025 | 87% | 31 |
| January 2026 | 87% | 31 |
| February 2026 | 79% | 28 |
| March 2026 | 90% | 30 |
| April 2026 | 90% | 30 |
| May 2026 | 74% | 31 |
- Departures on time
- 71%
- Diverted
- 0%
- Flights flown
- 359
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 361 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.