Flight number record
DL 1439
Delta Air Lines · Boston to Tampa
- Route
- BOS → TPA
- Departs
- 15:40
- Flights
- 345
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1439, check with Delta Air Lines.
DL 1439 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 345 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.3%, so DL 1439 runs 6 points behind the country as a whole. Across a thousand flights that is about 57 extra late arrivals.
Key figures
On time
71.6%
Arrivals under 15 minutes late, of 335 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
2.61%
National rate is 1.89%
1 hour+ late
13.1%
National rate is 8.3%
These figures cover 345 flights between September 2025 and August 2026. Beyond the headline rate, 13.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Schedule
When DL 1439 flies
DL 1439 flies BOS to TPA without a single fixed slot. Its most common scheduled departure was 15:40, used on 54 of 345 flights, with 15:35 (51 flights) and 16:19 (50 flights) next.
- Departs 15:4054 flights15.7%
- Departs 15:3551 flights14.8%
- Departs 16:1950 flights14.5%
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 15:40 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and DL 1439 runs level with that at 71.6%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
DL 1439 next to BOS to TPA
Every carrier on BOS to TPA combined arrived on time 74.4% of the time across 2,780 flights, so DL 1439 is 3 points behind it. Delta flew 1,169 flights on the same city pair under all its flight numbers, including this one, and those ran 76.3% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1439thin sample | 345 | 71.6% | 81 min | 2.61% | C |
| All Delta Air Lines on BOS–TPA | 1,169 | 76.3% | 73 min | 2.05% | B |
| All carriers on BOS–TPA | 2,780 | 74.4% | 70 min | 3.13% | C− |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1439 quarter by quarter
DL 1439 did not run the same all year. Its best quarter was Apr–Jun 2026 at 82.2% on time and its weakest Jul–Sep 2025 at 53.3%, a swing of 29 points on roughly 69 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 flights53.3%
- Oct–Dec 202582 flights66.7%
- Jan–Mar 202680 flights76.3%
- Apr–Jun 202691 flights82.2%
- Jul–Sep 202662 flights65.6%
Scale runs 45% to 90%.
By weekday, DL 1439 did best on Wednesday at 90.2% on time and worst on Sunday at 60.9%. Each day rests on about 49 flights, so a gap of 29 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1439 runs when it is late
DL 1439 often beats the schedule: 96 of 335 completed flights, 29%, arrived 15 minutes or more early. The 95 late arrivals split 22 under half an hour, 29 between 30 and 60 minutes, and 44 an hour or more.
- 15+ min early96 flights28.7%
- Within 15 min144 flights43.0%
- 15–29 min late22 flights6.6%
- 30–59 min late29 flights8.7%
- 1–2 hours late21 flights6.3%
- 2+ hours late23 flights6.9%
Scale runs 0% to 100%.
Share of 335 completed flights by arrival against schedule.
29 of 111 late departures made up the time and arrived on time, 26% of them. 13 flights left on time and still arrived late.
The worst days
Worst days for DL 1439
The latest arrival of the period was on 26 January 2026, 6 hours 33 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across January, March, February and October, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 January 2026 | 6 hours 33 minutes | Carrier |
| 17 March 2026 | 4 hours 13 minutes | Late-arriving aircraft |
| 20 February 2026 | 4 hours 6 minutes | Carrier |
| 16 March 2026 | 3 hours 56 minutes | National Airspace System |
| 13 October 2025 | 3 hours 52 minutes | Late-arriving aircraft |
Delay causes
Why DL 1439 runs late
Late-arriving aircraft accounts for 47% of the 7,652 delay minutes carriers reported here, and the remaining four split what is left.
- 47%Late-arriving aircraft
- 31%Carrier
- 21%National Airspace System
- 0%Extreme weather
47% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,652 reported delay minutes here, that single category outweighs weather by 47 to one. The split is drawn from 7,652 delay minutes reported on DL 1439.
Cancellations run at 2.61%, against 1.89% nationally. That is about one flight in 40 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
13.1% 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 1,185 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.
DL 1439 is not only a BOS to TPA flight. It also flew TPA to BOS (313 flights, 68.1% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 345 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| TPA to BOSthin sample | 313 | 68.1% | 75 min | 3.19% | C− |
What to do with this
Booking DL 1439
For a booking, the cancellation rate is the figure to plan around on DL 1439: 2.61% of its 345 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
- BOS to TPA, every carrier and departure
- TPA to BOS, the return direction
- JetBlue Airways 391 on the same route59.1%
- JetBlue Airways 891 on the same route90.3%
- JetBlue Airways 591 on the same route59.4%
- Delta Air Lines 2234 on the same route63.4%
- Boston Logan International (BOS) delay statistics
- Tampa International (TPA) 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.