Flight Reliability
DL 1403 · Delta Air Lines
Atlanta → St. Louis (ATL–STL)
77
Usually Fine
WanderNerd Reliability Score
- 77%
- Arrive within 15 minutes
- 9 min
- Average arrival delay
- 1.5%
- Cancelled
- 4 min early
- Median arrival delay
Based on 330 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
DL 1403 arrived on time 86% of the time on Sundays and just 63% on Fridays. That gap is worth planning around.
A bit behind the ATL–STL route.
DL 1403 arrived on time 77% of the time, versus 82% across the ATL–STL route.
A bit behind the Delta Air Lines network.
DL 1403 arrived on time 77% of the time, versus 81% across the Delta Air Lines network.
Ticking up lately.
DL 1403 arrived on time 82% of the time over the last three months in the data, compared with 78% in the three months before that.
The breakdown
- Mon70%(50 flights)
- Tue83%(42 flights)
- Wed76%(42 flights)
- Thu80%(50 flights)
- Fri63%(48 flights)
- Sat79%(43 flights)
- Sun86%(49 flights)
87%
May
Jun 48% → May 87% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 48% | 29 |
| July 2025 | 50% | 30 |
| August 2025 | 77% | 31 |
| September 2025 | 100% | 30 |
| October 2025 | 94% | 18 |
| November 2025 | 67% | 15 |
| December 2025 | 70% | 23 |
| January 2026 | 87% | 30 |
| February 2026 | 79% | 28 |
| March 2026 | 79% | 29 |
| April 2026 | 80% | 30 |
| May 2026 | 87% | 31 |
- Departures on time
- 78%
- Diverted
- 0.3%
- Flights flown
- 324
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 330 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.