Flight Reliability
DL 843 · Delta Air Lines
Atlanta → San Diego (ATL–SAN)82% of its flights flew this route. The rest (DFW–SLC, SLC–DFW) are included in these numbers.
86
Pretty Reliable
WanderNerd Reliability Score
- 83%
- Arrive within 15 minutes
- 5 min
- Average arrival delay
- 0.8%
- Cancelled
- 4 min early
- Median arrival delay
Based on 369 historical flights. Data through May 2026.
What the data says
6–9 PM has a slight edge.
Departures between 6–9 PM arrived on time 87% of the time, against 82% between 12–3 PM.
Monday is the weak spot.
DL 843 arrived on time 89% of the time on Wednesdays. On Mondays: 75%.
A bit ahead of the ATL–SAN route.
DL 843 arrived on time 83% of the time, versus 78% across the ATL–SAN route.
The breakdown
- Mon75%(52 flights)
- Tue86%(51 flights)
- Wed89%(52 flights)
- Thu77%(52 flights)
- Fri87%(52 flights)
- Sat83%(54 flights)
- Sun83%(52 flights)
- 12–3 PM82%(304 flights)
- 3–6 PM—(1 flights)
- 6–9 PM87%(60 flights)
84%
May
Jun 73% → May 84% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 73% | 30 |
| July 2025 | 74% | 31 |
| August 2025 | 90% | 31 |
| September 2025 | 90% | 30 |
| October 2025 | 90% | 30 |
| November 2025 | 80% | 30 |
| December 2025 | 70% | 30 |
| January 2026 | 90% | 29 |
| February 2026 | 84% | 31 |
| March 2026 | 94% | 32 |
| April 2026 | 73% | 30 |
| May 2026 | 84% | 31 |
- Departures on time
- 84%
- Diverted
- 0.3%
- Flights flown
- 365
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 369 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.