Carrier route record

B6BOS→SAN

JetBlue Airways · Boston to San Diego

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 BOS to SAN lands a B, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 919 flights, with a median arrival 12 minutes early.

Set against the rest of the country, JetBlue's BOS to SAN record is 5 points better than the US average of 77.3%. That gap is worth roughly 51 fewer late arrivals for every thousand flights.

On time

82.4%

Arrivals under 15 minutes late, of 897 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

1.96%

National rate is 1.89%

Whole route

75.3%

Every carrier on BOS to SAN, 1,880 flights

These figures cover 919 flights between September 2025 and August 2026. The median arrival is 12 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.

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Carrier by carrier

JetBlue against every carrier on BOS to SAN

JetBlue flew 919 of the 1,880 flights on BOS to SAN, about 49% of it. Its 82.4% on time is 7 points better than the route as a whole, which runs 75.3%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from JetBlue at 82.4% to Southwest at 44.8%. 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	82.4%	69 min	1.96%	B
Alaska Airlines	508	74.6%	71 min	1.57%	C
Delta Air Linesthin sample	364	66.0%	44 min	1.65%	C
Southwest Airlinesthin sample	89	44.8%	67 min	2.25%	F

Flight by flight

JetBlue flight numbers on BOS to SAN

B6 61906:0587.2% · 263 flights

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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 15 points, against half a point between the best and worst carrier.

5am–8am261 flights89.9%
8am–11am293 flights84.5%
11am–2pm1 flights—
2pm–5pm357 flights75.1%
5pm–8pm7 flights—
8pm–5am—

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.9% of the time, against 75.1% for the afternoon window. That is 15 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.May best, August worst

August is the worst month at 72.9% on time, 17 points below May, the best at 90.2%. 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, Monday is the strongest day at 86.0% on time and Wednesday the weakest at 79.2%, a spread of 7 points.

Arrival by arrival

How late JetBlue on BOS to SAN runs when it is late

JetBlue on BOS to SAN often beats the schedule: 411 of 897 completed flights, 46%, arrived 15 minutes or more early. The 158 late arrivals split 47 under half an hour, 43 between 30 and 60 minutes, and 68 an hour or more.

15+ min early411 flights45.8%
Within 15 min328 flights36.6%
15–29 min late47 flights5.2%
30–59 min late43 flights4.8%
1–2 hours late46 flights5.1%
2+ hours late22 flights2.5%

Scale runs 0% to 100%.

Share of 897 completed flights by arrival against schedule.

A late pushback is often recovered here: of 166 departures that left 15 minutes late or more, 50 still arrived on time. 42 flights left on time and still arrived late.

The worst days

Worst days for JetBlue on BOS to SAN

The latest arrival of the period was on 3 August 2026, 10 hours 56 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.

The latest arrivals of JetBlue on BOS to SAN in the period
Date	Arrived late by	Largest filed cause
3 August 2026	10 hours 56 minutes	Late-arriving aircraft
17 April 2026	5 hours 26 minutes	Late-arriving aircraft
27 December 2025	3 hours 57 minutes	Late-arriving aircraft
26 September 2025	3 hours 43 minutes	Late-arriving aircraft
8 June 2026	3 hours 32 minutes	Late-arriving aircraft

Delay causes

Why JetBlue runs late on this route

Late-arriving aircraft accounts for 45% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
45%
National Airspace System
25%
Carrier
23%
Extreme weather
6%
Security
0%

45% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 11,000 reported delay minutes here, that single category outweighs weather by 7 to one. The split is drawn from 10,874 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 89.9% on time here.

Cancellations sit at 1.96% against a national 1.89%, which is ordinary. Diversions add another 0.44%.

Connections and stage length

What a delay here costs

7.6% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over 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 76.6% 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 82.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 897 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures