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Flight Reliability

DL 4959 · Delta Air Lines

Jacksonville → New York (JAX–JFK)96% of its flights flew this route. The rest (MEM–LGA, GSO–ATL) are included in these numbers.

79
Usually Fine
WanderNerd Reliability Score
92%
Arrive within 15 minutes
4 min early
Average arrival delay
5.0%
Cancelled
14 min early
Median arrival delay

Based on 362 historical flights. Data through May 2026.

What the data says

Tuesday is the weak spot.

DL 4959 arrived on time 100% of the time on Wednesdays. On Tuesdays: 88%.

Better than the JAX–JFK route average.

DL 4959 arrived on time 92% of the time, versus 79% across the JAX–JFK route.

Better than the Delta Air Lines network average.

DL 4959 arrived on time 92% of the time, versus 81% across the Delta Air Lines network.

Keep a backup plan handy.

DL 4959 was cancelled 5.0% of the time. Typical for U.S. flights is around 1–2%.

The breakdown

On-time by weekday
  • Mon92%(49 flights)
  • Tue88%(49 flights)
  • Wed100%(49 flights)
  • Thu89%(46 flights)
  • Fri92%(50 flights)
  • Sat92%(52 flights)
  • Sun90%(48 flights)
On-time by departure window
  • 6–9 AM92%(342 flights)
  • 9 AM–12 PM—(1 flights)
On-time trend by month
93%
May

Jun 96% → May 93% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202596%28
July 2025100%26
August 202593%30
September 202590%30
October 202594%31
November 202593%29
December 202589%28
January 202688%25
February 202677%26
March 202693%30
April 202693%30
May 202693%30
Departures on time
93%
Diverted
0.3%
Flights flown
343
Months covered
12

Same route, other flights

Keep nerding

Based on 362 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.