Flight number record
B6 904
JetBlue Airways · San Juan to New York
- Route
- SJU → JFK
- Departs
- 13:25
- Flights
- 309
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s B6 904, check with JetBlue Airways.
B6 904 lands a B, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 309 flights, with a median arrival 5 minutes early.
Key figures
On time
77.7%
Arrivals under 15 minutes late, of 300 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
2.91%
National rate is 1.89%
1 hour+ late
6.3%
National rate is 8.3%
These figures cover 309 flights between September 2025 and August 2026. The median arrival is 5 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When B6 904 flies
B6 904 flies SJU to JFK without a single fixed slot. Its most common scheduled departure was 13:25, used on 42 of 309 flights, with 07:55 (33 flights) next.
- Departs 13:2542 flights13.6%
- Departs 07:5533 flights10.7%
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 13:25 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and B6 904 runs level with that at 77.7%. 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 904 next to SJU to JFK
Every carrier on SJU to JFK combined arrived on time 77.8% of the time across 3,560 flights, so B6 904 is about level with it. JetBlue flew 2,250 flights on the same city pair under all its flight numbers, including this one, and those ran 72.4% on time. Across its whole network JetBlue Airways managed 71.3%, which this flight beats by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| B6 904thin sample | 309 | 77.7% | 76 min | 2.91% | B |
| All JetBlue Airways on SJU–JFK | 2,250 | 72.4% | 85 min | 4.84% | C− |
| All carriers on SJU–JFK | 3,560 | 77.8% | 82 min | 3.93% | B− |
| JetBlue Airways, whole network | 240,615 | 71.3% | 77 min | 3.56% | C− |
Across the year
B6 904 quarter by quarter
B6 904 did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.5% on time and its weakest Jul–Sep 2025 at 63.3%, a swing of 25 points on roughly 62 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 flights63.3%
- Oct–Dec 202575 flights73.0%
- Jan–Mar 202690 flights74.4%
- Apr–Jun 202652 flights88.5%
- Jul–Sep 202662 flights86.2%
Scale runs 55% to 95%.
By weekday, B6 904 did best on Wednesday at 84.1% on time and worst on Tuesday at 68.2%. Each day rests on about 44 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late B6 904 runs when it is late
B6 904 often beats the schedule: 97 of 300 completed flights, 32%, arrived 15 minutes or more early. The 67 late arrivals split 25 under half an hour, 23 between 30 and 60 minutes, and 19 an hour or more.
- 15+ min early97 flights32.3%
- Within 15 min136 flights45.3%
- 15–29 min late25 flights8.3%
- 30–59 min late23 flights7.7%
- 1–2 hours late10 flights3.3%
- 2+ hours late9 flights3.0%
Scale runs 0% to 100%.
Share of 300 completed flights by arrival against schedule.
A late pushback is often recovered here: of 77 departures that left 15 minutes late or more, 25 still arrived on time. In the other direction, 15 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 JFK.
The worst days
Worst days for B6 904
The latest arrival of the period was on 21 October 2025, 6 hours 27 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 October 2025 | 6 hours 27 minutes | Carrier |
| 4 November 2025 | 6 hours 26 minutes | Late-arriving aircraft |
| 30 June 2026 | 6 hours 1 minute | Late-arriving aircraft |
| 23 January 2026 | 5 hours 10 minutes | National Airspace System |
| 23 July 2026 | 4 hours 59 minutes | Late-arriving aircraft |
Delay causes
Why B6 904 runs late
Carrier accounts for 51% of the 5,074 delay minutes carriers reported here, and the remaining four split what is left.
- 51%Carrier
- 35%Late-arriving aircraft
- 14%National Airspace System
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,074 reported delay minutes here, that single category outweighs weather by 35 to one. The split is drawn from 5,074 delay minutes reported on B6 904.
Cancellations run at 2.91%, against 1.89% nationally. That is roughly 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
6.3% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
At 1,598 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 309 flights under B6 904 in the data flew SJU to JFK. 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. 309 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 904
For a booking, the cancellation rate is the figure to plan around on B6 904: 2.91% of its 309 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
- SJU to JFK, every carrier and departure
- JFK to SJU, the return direction
- Delta Air Lines 1854 on the same route92.5%
- JetBlue Airways 1604 on the same route79.9%
- Delta Air Lines 1961 on the same route87.7%
- Delta Air Lines 1966 on the same route83.6%
- JetBlue Airways 1004 on the same route64.2%
- Luis Munoz Marin International (SJU) delay statistics
- John F. Kennedy International (JFK) 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.