Flight number record
DL 1638
Delta Air Lines · New York to West Palm Beach
- Route
- JFK → PBI
- Departs
- 16:20
- Flights
- 333
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1638, check with Delta Air Lines.
DL 1638 sits in the middle of the pack with a C−. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 333 flights, with a median arrival 7 minutes early.
The national on-time rate over the same period is 77.3%, so DL 1638 runs 4 points behind the country as a whole. Across a thousand flights that is about 42 extra late arrivals.
Key figures
On time
73.1%
Arrivals under 15 minutes late, of 316 completed flights
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
4.80%
National rate is 1.89%
1 hour+ late
11.7%
National rate is 8.3%
These figures cover 333 flights between September 2025 and August 2026. Beyond the headline rate, 11.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 1638 flies
DL 1638 flies JFK to PBI without a single fixed slot. Its most common scheduled departure was 16:20, used on 84 of 333 flights, with 16:00 (53 flights) next.
- Departs 16:2084 flights25.2%
- Departs 16:0053 flights15.9%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:20 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and DL 1638 runs level with that at 73.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 1638 next to JFK to PBI
Every carrier on JFK to PBI combined arrived on time 74.8% of the time across 2,050 flights, so DL 1638 is 2 points behind it. Delta flew 667 flights on the same city pair under all its flight numbers, including this one, and those ran 80.9% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1638thin sample | 333 | 73.1% | 82 min | 4.80% | C− |
| All Delta Air Lines on JFK–PBI | 667 | 80.9% | 75 min | 4.65% | B− |
| All carriers on JFK–PBI | 2,050 | 74.8% | 71 min | 4.59% | C− |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1638 quarter by quarter
DL 1638 did not run the same all year. Its best quarter was Apr–Jun 2026 at 79.3% on time and its weakest Oct–Dec 2025 at 66.3%, a swing of 13 points on roughly 83 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights76.7%
- Oct–Dec 202591 flights66.3%
- Jan–Mar 202690 flights72.9%
- Apr–Jun 202691 flights79.3%
- Jul–Sep 202631 flights—
Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1638 did best on Saturday at 81.4% on time and worst on Sunday at 60.5%. Each day rests on about 48 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1638 runs when it is late
DL 1638 often beats the schedule: 122 of 316 completed flights, 39%, arrived 15 minutes or more early. The 85 late arrivals split 22 under half an hour, 26 between 30 and 60 minutes, and 37 an hour or more.
- 15+ min early122 flights38.6%
- Within 15 min109 flights34.5%
- 15–29 min late22 flights7.0%
- 30–59 min late26 flights8.2%
- 1–2 hours late19 flights6.0%
- 2+ hours late18 flights5.7%
Scale runs 0% to 100%.
Share of 316 completed flights by arrival against schedule.
14 of 77 late departures made up the time and arrived on time, 18% of them. In the other direction, 22 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at PBI.
The worst days
Worst days for DL 1638
The latest arrival of the period was on 28 July 2026, 8 hours 50 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in July 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 July 2026 | 8 hours 50 minutes | National Airspace System |
| 21 July 2026 | 5 hours 3 minutes | National Airspace System |
| 19 July 2026 | 4 hours 35 minutes | Late-arriving aircraft |
| 26 May 2026 | 4 hours 20 minutes | Carrier |
| 28 December 2025 | 3 hours 55 minutes | Late-arriving aircraft |
Delay causes
Why DL 1638 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 6,956 reported delay minutes.
- 35%Late-arriving aircraft
- 34%National Airspace System
- 31%Carrier
- 0%Extreme weather
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,956 reported delay minutes here, that single category outweighs weather by 35 to one. The split is drawn from 6,956 delay minutes reported on DL 1638.
Cancellations run at 4.80%, against 1.89% nationally. That is about one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
11.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 1,028 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on one other city pair in the data, including PBI to JFK (162), but none flew often enough under DL 1638 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to JFK to PBI only.
One caution: this is a thin sample. 333 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking DL 1638
For a booking, the cancellation rate is the figure to plan around on DL 1638: 4.80% of its 333 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- JFK to PBI, every carrier and departure
- PBI to JFK, the return direction
- Delta Air Lines 2018 on the same route88.7%
- JetBlue Airways 1053 on the same route65.9%
- John F. Kennedy International (JFK) delay statistics
- Palm Beach International (PBI) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.