Carrier route record

B6BOS→SAN

JetBlue Airways · Boston to San Diego

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 BOS to SAN earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 919 flights, with a median arrival 13 minutes early.

Set against the rest of the country, JetBlue's BOS to SAN record is 7 points better than the US average of 77.6%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.

On time

84.9%

Arrivals under 15 minutes late, of 905 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

1.20%

National rate is 1.81%

Whole route

76.5%

Every carrier on BOS to SAN, 1,818 flights

These figures cover 919 flights between July 2025 and June 2026. The median arrival is 13 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.

Carrier by carrier

JetBlue against every carrier on BOS to SAN

JetBlue flew 919 of the 1,818 flights on BOS to SAN, most of the route. Its 84.9% on time is 8 points better than the route as a whole, which runs 76.5%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from JetBlue at 84.9% to Southwest at 29.6%. 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.

On-time performance by carrier on BOS to SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
JetBlue Airways (this page)	919	84.9%	64 min	1.20%	B
Alaska Airlines	508	69.8%	56 min	1.57%	C
Delta Air Linesthin sample	364	67.9%	43 min	1.65%	C
Southwest Airlinesthin sample	27	29.6%	72 min	0.00%	F+

Flight by flight

JetBlue flight numbers on BOS to SAN

B6 61907:0088.8% · 263 flights

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 13 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am261 flights91.5%
8am–11am293 flights86.5%
11am–2pm1 flights—
2pm–5pm357 flights78.6%
5pm–8pm7 flights—
8pm–5am—

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.5% of the time, against 78.6% for the afternoon window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 357 flights scheduled in it.

Across the year

JetBlue on BOS to SAN through the year

Darker means more delays. Figures are on-time percentages.August best, February worst

February is the weak month at 73.1% on time, against 94.3% in August. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 89 flights.

Across the week, Saturday is the strongest day at 87.8% on time and Friday the weakest at 83.5%. 4 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 8,797 reported delay minutes.

Late-arriving aircraft
41%
National Airspace System
28%
Carrier
26%
Extreme weather
5%

41% 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 8,797 reported delay minutes here, that single category outweighs weather by 9 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 8,797 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 91.5% on time here.

Cancellations sit at 1.20% against a national 1.81%, which is ordinary. Diversions add another 0.33%.

Connections and stage length

What a delay here costs

5.7% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

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 79.3% on time across 919 flights, 6 points below 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 BOS to SAN

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 84.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 905 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures