Flight number record
B6 391
JetBlue Airways · Boston to Tampa
- Route
- BOS → TPA
- Departs
- 16:19
- Flights
- 320
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s B6 391, check with JetBlue Airways.
B6 391 draws a D−. Roughly one flight in two arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 320 flights, with a median arrival 6 minutes late.
The national on-time rate over the same period is 77.3%, so B6 391 runs 18 points behind the country as a whole. Across a thousand flights that is about 182 extra late arrivals.
Key figures
On time
59.1%
Arrivals under 15 minutes late, of 308 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
3.12%
National rate is 1.89%
1 hour+ late
17.2%
National rate is 8.3%
These figures cover 320 flights between September 2025 and August 2026. Beyond the headline rate, 17.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When B6 391 flies
B6 391 flies BOS to TPA without a single fixed slot. Its most common scheduled departure was 16:19, used on 55 of 320 flights, with 17:10 (36 flights) next.
- Departs 16:1955 flights17.2%
- Departs 17:1036 flights11.3%
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 16:19 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and B6 391 runs 13 points worse at 59.1%. 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
B6 391 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 B6 391 is 15 points behind it. JetBlue flew 1,588 flights on the same city pair under all its flight numbers, including this one, and those ran 73.1% on time. Across its whole network JetBlue Airways managed 71.3%, which this flight trails by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| B6 391thin sample | 320 | 59.1% | 71 min | 3.12% | D− |
| All JetBlue Airways on BOS–TPA | 1,588 | 73.1% | 68 min | 3.90% | C− |
| All carriers on BOS–TPA | 2,780 | 74.4% | 70 min | 3.13% | C− |
| JetBlue Airways, whole network | 240,615 | 71.3% | 77 min | 3.56% | C− |
Across the year
B6 391 quarter by quarter
B6 391 did not run the same all year. Its best quarter was Apr–Jun 2026 at 72.7% on time and its weakest Jul–Sep 2026 at 43.6%, a swing of 29 points on roughly 80 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 20256 flights—
- Oct–Dec 202574 flights49.3%
- Jan–Mar 202690 flights65.1%
- Apr–Jun 202689 flights72.7%
- Jul–Sep 202661 flights43.6%
Scale runs 35% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, B6 391 did best on Thursday at 73.9% on time and worst on Sunday at 40.4%. Each day rests on about 46 flights, so a gap of 34 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late B6 391 runs when it is late
The 126 late arrivals split 36 under half an hour, 37 between 30 and 60 minutes, and 53 an hour or more.
- 15+ min early75 flights24.4%
- Within 15 min107 flights34.7%
- 15–29 min late36 flights11.7%
- 30–59 min late37 flights12.0%
- 1–2 hours late35 flights11.4%
- 2+ hours late18 flights5.8%
Scale runs 0% to 100%.
Share of 308 completed flights by arrival against schedule.
23 of 132 late departures made up the time and arrived on time, 17% of them. In the other direction, 17 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 TPA.
The worst days
Worst days for B6 391
The latest arrival of the period was on 2 December 2025, 5 hours 55 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in December 2025.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 December 2025 | 5 hours 55 minutes | Carrier |
| 28 December 2025 | 5 hours 15 minutes | Late-arriving aircraft |
| 22 July 2026 | 4 hours 38 minutes | Carrier |
| 15 August 2026 | 4 hours 23 minutes | National Airspace System |
| 19 December 2025 | 4 hours 8 minutes | Late-arriving aircraft |
Delay causes
Why B6 391 runs late
Late-arriving aircraft accounts for 52% of the 8,927 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Late-arriving aircraft
- 28%Carrier
- 19%National Airspace System
- 1%Extreme weather
52% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,927 reported delay minutes here, that single category outweighs weather by 52 to one. The split is drawn from 8,927 delay minutes reported on B6 391.
Cancellations run at 3.12%, against 1.89% nationally. That is about one flight in 30 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
17.2% 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.
Every one of the 320 flights under B6 391 in the data flew BOS to TPA. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 320 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 B6 391
For a booking, the cancellation rate is the figure to plan around on B6 391: 3.12% of its 320 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
- Delta Air Lines 1439 on the same route71.6%
- 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
- JetBlue Airways on-time record
- Every JetBlue Airways 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 JetBlue Airways’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.