Flight Reliability
DL 3973 · Delta Air Lines
Salt Lake City → SUN (SLC–SUN)
97
Nerd Approved
WanderNerd Reliability Score
- 94%
- Arrive within 15 minutes
- 5 min early
- Average arrival delay
- 0.6%
- Cancelled
- 9 min early
- Median arrival delay
Based on 361 historical flights. Data through May 2026.
What the data says
Sunday scaries are real for this one.
DL 3973 arrived on time 98% of the time on Tuesdays. On Sundays: 90%.
Better than the Delta Air Lines network average.
DL 3973 arrived on time 94% of the time, versus 81% across the Delta Air Lines network.
The breakdown
- Mon96%(52 flights)
- Tue98%(51 flights)
- Wed94%(49 flights)
- Thu92%(50 flights)
- Fri92%(51 flights)
- Sat94%(52 flights)
- Sun90%(52 flights)
100%
May
Jun 100% → May 100% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 100% | 30 |
| July 2025 | 97% | 31 |
| August 2025 | 94% | 31 |
| September 2025 | 100% | 30 |
| October 2025 | 87% | 31 |
| November 2025 | 93% | 29 |
| December 2025 | 96% | 28 |
| January 2026 | 90% | 30 |
| February 2026 | 89% | 28 |
| March 2026 | 97% | 31 |
| April 2026 | 83% | 30 |
| May 2026 | 100% | 28 |
- Departures on time
- 93%
- Diverted
- 0.6%
- Flights flown
- 357
- 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.