Carrier route record
B6SAN→BOS
JetBlue Airways · San Diego to Boston
- Flights
- 919
- Period
- September 2025 to August 2026
- Share of route
- 49%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with JetBlue Airways.
JetBlue on SAN to BOS lands a B, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 919 flights, with a median arrival 12 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate JetBlue on SAN to BOS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.6%
Arrivals under 15 minutes late, of 896 completed flights
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
2.07%
National rate is 1.89%
Whole route
75.5%
Every carrier on SAN to BOS, 1,881 flights
These figures cover 919 flights between September 2025 and August 2026. Beyond the headline rate, 12.2% 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.
Carrier by carrier
JetBlue against every carrier on SAN to BOS
JetBlue flew 919 of the 1,881 flights on SAN to BOS, about 49% of it. Its 76.6% on time is about level with the route as a whole at 75.5%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Alaska at 78.3% to Southwest at 38.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 509 | 78.3% | 72 min | 1.38% | B |
| Delta Air Linesthin sample | 364 | 78.2% | 91 min | 1.65% | B |
| JetBlue Airways (this page) | 919 | 76.6% | 92 min | 2.07% | B |
| Southwest Airlinesthin sample | 89 | 38.2% | 73 min | 0.00% | F+ |
Flight by flight
JetBlue flight numbers on SAN to BOS
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.
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 16 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am70 flights65.7%
- 11am–2pm330 flights73.7%
- 2pm–5pm155 flights75.3%
- 5pm–8pm—
- 8pm–5am364 flights81.7%
Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 81.7% on time across 364 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 364 flights scheduled in it.
Across the year
JetBlue on SAN to BOS through the year
July is the worst month at 62.2% on time, 27 points below May, the best at 89.0%. 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. March was the busiest month here, with 89 flights.
Across the week, Saturday is the strongest day at 82.2% on time and Thursday the weakest at 70.9%, a spread of 11 points.
Arrival by arrival
How late JetBlue on SAN to BOS runs when it is late
JetBlue on SAN to BOS often beats the schedule: 413 of 896 completed flights, 46%, arrived 15 minutes or more early. When JetBlue on SAN to BOS is late it tends to be very late: 109 of its 210 late arrivals were an hour or more behind, and 33 were two hours or more.
- 15+ min early413 flights46.1%
- Within 15 min273 flights30.5%
- 15–29 min late43 flights4.8%
- 30–59 min late58 flights6.5%
- 1–2 hours late76 flights8.5%
- 2+ hours late33 flights3.7%
Scale runs 0% to 100%.
Share of 896 completed flights by arrival against schedule.
69 of 251 late departures made up the time and arrived on time, 27% of them. 28 flights left on time and still arrived late.
The worst days
Worst days for JetBlue on SAN to BOS
The latest arrival of the period was on 18 January 2026, 21 hours 30 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, September, March and October, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 January 2026 | 21 hours 30 minutes | Carrier |
| 17 September 2025 | 15 hours 1 minute | Late-arriving aircraft |
| 8 March 2026 | 14 hours 22 minutes | Extreme weather |
| 13 October 2025 | 13 hours 51 minutes | Carrier |
| 8 March 2026 | 8 hours 56 minutes | Late-arriving aircraft |
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 19,000 reported delay minutes.
- 37%Late-arriving aircraft
- 30%National Airspace System
- 25%Carrier
- 7%Extreme weather
- 0%Security
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 19,000 reported delay minutes here, that single category outweighs weather by 5 to one. The split is drawn from 19,259 reported delay minutes.
Cancellations sit at 2.07% against a national 1.89%, which is ordinary. Diversions add another 0.44%.
Connections and stage length
What a delay here costs
12.2% 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.
At 2,588 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 82.4% on time across 919 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 919 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 JetBlue on SAN to BOS
Put together: treat all of this as provisional. 919 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 76.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 896 completed flights over 12 months sit behind that.
Related
Where to go next
- SAN to BOS, every carrier
- JetBlue on BOS to SAN, the return leg
- Alaska Airlines on SAN to BOS78.3%
- Delta Air Lines on SAN to BOS78.2%
- JetBlue Airways network-wide record
- San Diego International (SAN) delay statistics
- Boston Logan International (BOS) 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.