Flight Reliability
DL 2023 · Delta Air Lines
Philadelphia → Salt Lake City (PHL–SLC)
86
Pretty Reliable
WanderNerd Reliability Score
- 85%
- Arrive within 15 minutes
- 2 min
- Average arrival delay
- 1.9%
- Cancelled
- 3 min early
- Median arrival delay
Based on 364 historical flights. Data through May 2026.
What the data says
Sunday scaries are real for this one.
DL 2023 arrived on time 92% of the time on Tuesdays. On Sundays: 79%.
Better than the PHL–SLC route average.
DL 2023 arrived on time 85% of the time, versus 78% across the PHL–SLC route.
A bit ahead of the Delta Air Lines network.
DL 2023 arrived on time 85% of the time, versus 81% across the Delta Air Lines network.
Trending in the right direction.
DL 2023 arrived on time 93% of the time over the last three months in the data, compared with 72% in the three months before that.
The breakdown
- Mon82%(50 flights)
- Tue92%(50 flights)
- Wed90%(52 flights)
- Thu84%(51 flights)
- Fri87%(52 flights)
- Sat84%(50 flights)
- Sun79%(52 flights)
93%
May
Jun 83% → May 93% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 83% | 29 |
| July 2025 | 83% | 30 |
| August 2025 | 93% | 30 |
| September 2025 | 90% | 30 |
| October 2025 | 90% | 31 |
| November 2025 | 90% | 30 |
| December 2025 | 53% | 30 |
| January 2026 | 77% | 30 |
| February 2026 | 85% | 26 |
| March 2026 | 87% | 31 |
| April 2026 | 100% | 30 |
| May 2026 | 93% | 30 |
- Departures on time
- 88%
- Diverted
- 0%
- Flights flown
- 357
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 364 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.