Carrier route record
B6SAN→BOS
JetBlue Airways · San Diego to Boston
- Flights
- 919
- Period
- July 2025 to June 2026
- Share of route
- 51%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with JetBlue Airways.
JetBlue on SAN to BOS lands a B, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 919 flights, with a median arrival 14 minutes early.
The US average over the same twelve months is 77.6%, 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
79.3%
Arrivals under 15 minutes late, of 904 completed flights
Avg delay
99 min
Across delayed arrivals only, not all flights
Cancelled
1.41%
National rate is 1.81%
Whole route
77.9%
Every carrier on SAN to BOS, 1,818 flights
These figures cover 919 flights between July 2025 and June 2026. Beyond the headline rate, 9.8% 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 SAN to BOS
JetBlue flew 919 of the 1,818 flights on SAN to BOS, most of the route. Its 79.3% on time is about level with the route as a whole at 77.9%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from JetBlue at 79.3% to Southwest at 44.4%. 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 |
|---|---|---|---|---|---|
| JetBlue Airways (this page) | 919 | 79.3% | 99 min | 1.41% | B |
| Delta Air Linesthin sample | 364 | 79.3% | 86 min | 1.65% | B |
| Alaska Airlines | 508 | 76.2% | 66 min | 1.77% | B |
| Southwest Airlinesthin sample | 27 | 44.4% | 69 min | 0.00% | F+ |
Flight by flight
JetBlue flight numbers on SAN to BOS
Departure window
When JetBlue runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 919 flights.
- 5am–8am—
- 8am–11am17 flights—
- 11am–2pm382 flights76.0%
- 2pm–5pm156 flights75.5%
- 5pm–8pm—
- 8pm–5am364 flights84.8%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 84.8% 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 11am–2pm window is the busiest, with 382 flights scheduled in it.
Across the year
JetBlue on SAN to BOS through the year
July is the worst month at 73.0% on time, 16 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 88.9% on time and Thursday the weakest at 72.4%. 17 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 18,000 reported delay minutes.
- 33%Carrier
- 32%Late-arriving aircraft
- 27%National Airspace System
- 7%Extreme weather
- 0%Security
No single cause dominates. carrier at 33%, late-arriving aircraft at 32% and national airspace system at 27% split the 18,000 reported delay minutes between them. An even spread like this usually means the operation is running close to its designed capacity with no one obvious weak point, and it is the hardest pattern for a traveller to route around. The split is drawn from 18,446 reported delay minutes.
Cancellations sit at 1.41% against a national 1.81%, which is ordinary. Diversions add another 0.22%.
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. 9.8% 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 2,588 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 84.9% 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 79.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 904 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
- Delta Air Lines on SAN to BOS79.3%
- Alaska Airlines on SAN to BOS76.2%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.