Flight Reliability
DL 5239 · Delta Air Lines
Raleigh–Durham → New York (RDU–JFK)
81
Pretty Reliable
WanderNerd Reliability Score
- 89%
- Arrive within 15 minutes
- 0 min
- Average arrival delay
- 4.0%
- Cancelled
- 12 min early
- Median arrival delay
Based on 348 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
DL 5239 arrived on time 94% of the time on Saturdays and just 76% on Fridays. That gap is worth planning around.
Better than the RDU–JFK route average.
DL 5239 arrived on time 89% of the time, versus 76% across the RDU–JFK route.
Better than the Delta Air Lines network average.
DL 5239 arrived on time 89% of the time, versus 81% across the Delta Air Lines network.
Keep a backup plan handy.
DL 5239 was cancelled 4.0% of the time. Typical for U.S. flights is around 1–2%.
The breakdown
- Mon93%(45 flights)
- Tue89%(47 flights)
- Wed90%(49 flights)
- Thu92%(49 flights)
- Fri76%(49 flights)
- Sat94%(48 flights)
- Sun92%(47 flights)
93%
May
Jun 93% → May 93% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 93% | 29 |
| July 2025 | 90% | 30 |
| August 2025 | 83% | 29 |
| September 2025 | 90% | 30 |
| October 2025 | 97% | 31 |
| November 2025 | 90% | 29 |
| December 2025 | 83% | 18 |
| January 2026 | 91% | 22 |
| February 2026 | 92% | 26 |
| March 2026 | 74% | 31 |
| April 2026 | 93% | 29 |
| May 2026 | 93% | 30 |
- Departures on time
- 90%
- Diverted
- 0%
- Flights flown
- 334
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 348 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.