Carrier route record
B6BOS→SFO
JetBlue Airways · Boston to San Francisco
- Flights
- 1,676
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with JetBlue Airways.
JetBlue on BOS to SFO sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,676 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,867 at 76.3% on time.
The national on-time rate over the same period is 77.6%, so JetBlue on BOS to SFO runs 7 points behind the country as a whole. Across a thousand flights that is about 71 extra late arrivals.
Key figures
On time
70.5%
Arrivals under 15 minutes late, of 1,649 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
1.31%
National rate is 1.81%
Whole route
72.6%
Every carrier on BOS to SFO, 4,676 flights
These figures cover 1,676 flights between July 2025 and June 2026. Beyond the headline rate, 10.2% 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.
Carrier by carrier
JetBlue against every carrier on BOS to SFO
JetBlue flew 1,676 of the 4,676 flights on BOS to SFO, about 36% of it. Its 70.5% on time is 2 points worse than the route as a whole, which runs 72.6%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Southwest at 100.0% to Alaska at 61.6%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| United Airlines | 1,867 | 76.3% | 66 min | 1.12% | B |
| Delta Air Lines | 898 | 71.8% | 63 min | 1.45% | C |
| JetBlue Airways (this page) | 1,676 | 70.5% | 65 min | 1.31% | C |
| Alaska Airlinesthin sample | 234 | 61.6% | 66 min | 0.43% | D+ |
No carrier stands out. United tops the table at 76.3%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
JetBlue flight numbers on BOS to SFO
Departure window
When JetBlue runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 29 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am362 flights86.7%
- 8am–11am339 flights80.1%
- 11am–2pm63 flights58.7%
- 2pm–5pm343 flights63.9%
- 5pm–8pm249 flights58.1%
- 8pm–5am320 flights61.0%
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 58.1% on time, against 86.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 362 flights scheduled in it.
Across the year
JetBlue on BOS to SFO through the year
June is the worst month at 58.2% on time, 29 points below August, the best at 87.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. June was the busiest month here, with 203 flights.
Across the week, Tuesday is the strongest day at 78.7% on time and Thursday the weakest at 66.7%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why JetBlue runs late on this route
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 32,000 reported delay minutes.
- 39%Late-arriving aircraft
- 35%National Airspace System
- 22%Carrier
- 3%Extreme weather
- 0%Security
39% 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 32,000 reported delay minutes here, that single category outweighs weather by 12 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 31,556 reported delay minutes.
35% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 11,000 minutes out of 32,000, against a national NAS share of 21%.
Cancellations sit at 1.31% against a national 1.81%, which is ordinary. Diversions add another 0.30%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.2% 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.
The return leg is a different operation and performs like one: it runs 75.4% on time across 1,674 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
The sample behind these figures is 1,676 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking JetBlue on BOS to SFO
Put together: the calendar is the biggest lever here, not the carrier or the hour. August runs 87.3% on time and June 58.2%, a swing of 29 points. If the dates move at all, move them out of June before you think about anything else. 1,649 completed flights over 12 months sit behind that.
Related
Where to go next
- BOS to SFO, every carrier
- JetBlue on SFO to BOS, the return leg
- United Airlines on BOS to SFO76.3%
- Delta Air Lines on BOS to SFO71.8%
- Alaska Airlines on BOS to SFO61.6%
- JetBlue Airways network-wide record
- Boston Logan International (BOS) delay statistics
- San Francisco International (SFO) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.