Flight number record
B6 733
JetBlue Airways · Boston to San Francisco
- Route
- BOS → SFO
- Departs
- 18:30
- Flights
- 331
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s B6 733, check with JetBlue Airways.
B6 733 draws a D. Roughly one flight in three 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 331 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.6%, so B6 733 runs 17 points behind the country as a whole. Across a thousand flights that is about 170 extra late arrivals.
Key figures
On time
60.6%
Arrivals under 15 minutes late, of 325 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
1.21%
National rate is 1.81%
1 hour+ late
16.0%
National rate is 8.1%
These figures cover 331 flights between July 2025 and June 2026. Beyond the headline rate, 16.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When B6 733 flies
B6 733 flies BOS to SFO without a single fixed slot. Its most common scheduled departure was 18:30, used on 64 of 331 flights, with 17:59 (42 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 18:3064 flights19.3%
- Departs 17:5942 flights12.7%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 18:30 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and B6 733 runs 8 points worse at 60.6%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
B6 733 next to BOS to SFO
Every carrier on BOS to SFO combined arrived on time 72.6% of the time across 4,676 flights, so B6 733 is 12 points behind it. JetBlue flew 1,676 flights on the same city pair under all its flight numbers, including this one, and those ran 70.5% on time. Across its whole network JetBlue Airways managed 72.7%, which this flight trails by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| B6 733thin sample | 331 | 60.6% | 74 min | 1.21% | D |
| All JetBlue Airways on BOS–SFO | 1,676 | 70.5% | 65 min | 1.31% | C |
| All carriers on BOS–SFO | 4,676 | 72.6% | 65 min | 1.22% | C |
| JetBlue Airways, whole network | 234,468 | 72.7% | 76 min | 2.56% | C |
Across the year
B6 733 quarter by quarter
B6 733 did not run the same all year. Its best quarter was Jul–Sep 2025 at 72.4% on time and its weakest Apr–Jun 2026 at 47.0%, a swing of 25 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 202588 flights72.4%
- Oct–Dec 202587 flights58.1%
- Jan–Mar 202690 flights61.6%
- Apr–Jun 202666 flights47.0%
Scale runs 40% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, B6 733 did best on Tuesday at 75.5% on time and worst on Thursday at 45.8%. Each day rests on about 47 flights, so a gap of 30 points is worth noticing but could still narrow in another year.
Delay causes
Why B6 733 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 9,425 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 43%Late-arriving aircraft
- 31%National Airspace System
- 23%Carrier
- 3%Extreme weather
43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 9,425 reported delay minutes here, that single category outweighs weather by 14 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 9,425 delay minutes reported on B6 733.
Cancellations sit at 1.21% against a national 1.81%, which is ordinary. Diversions add another 0.60%.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 16.0% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 2,704 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 331 flights under B6 733 in the data flew BOS to SFO. 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. 331 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 733
For a booking, B6 733 is a flight to put a long connection behind. 16.0% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- BOS to SFO, every carrier and departure
- SFO to BOS, the return direction
- Delta Air Lines 1655 on the same route67.0%
- JetBlue Airways 333 on the same route56.9%
- United Airlines 2400 on the same route58.4%
- United Airlines 2441 on the same route83.5%
- United Airlines 1074 on the same route81.5%
- Boston Logan International (BOS) delay statistics
- San Francisco International (SFO) 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.