Carrier route record

B6JFK→SJU

JetBlue Airways · New York to San Juan

Flights: 2,232
Period: July 2025 to June 2026
Share of route: 61%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with JetBlue Airways.

JetBlue on JFK to SJU sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 2,232 flights, with a median arrival 4 minutes early.

The national on-time rate over the same period is 77.6%, so JetBlue on JFK to SJU runs 8 points behind the country as a whole. Across a thousand flights that is about 81 extra late arrivals.

On time

69.5%

Arrivals under 15 minutes late, of 2,164 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

2.91%

National rate is 1.81%

Whole route

71.1%

Every carrier on JFK to SJU, 3,651 flights

These figures cover 2,232 flights between July 2025 and June 2026. Beyond the headline rate, 12.5% 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 JFK to SJU

JetBlue flew 2,232 of the 3,651 flights on JFK to SJU, most of the route. Its 69.5% on time is 2 points worse than the route as a whole, which runs 71.1%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 78.8% to Frontier at 56.1%. One 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 JFK to SJU
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,104	78.8%	60 min	1.99%	B
JetBlue Airways (this page)	2,232	69.5%	74 min	2.91%	C
Frontier Airlinesthin sample	315	56.1%	99 min	2.86%	D

Flight by flight

JetBlue flight numbers on JFK to SJU

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 20 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–8am358 flights83.1%
8am–11am402 flights72.1%
11am–2pm353 flights66.7%
2pm–5pm250 flights71.3%
5pm–8pm387 flights62.8%
8pm–5am482 flights63.7%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 62.8% on time, against 83.1% 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 8pm–5am window is the busiest, with 482 flights scheduled in it.

Across the year

JetBlue on JFK to SJU through the year

Darker means more delays. Figures are on-time percentages.May best, October worst

May is the best month on the calendar at 82.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 217 flights.

Across the week, Tuesday is the strongest day at 75.9% on time and Thursday the weakest at 63.5%. 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 49,000 reported delay minutes.

Late-arriving aircraft
41%
Carrier
35%
National Airspace System
21%
Extreme weather
2%
Security
1%

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 49,000 reported delay minutes here, that single category outweighs weather by 22 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 48,823 reported delay minutes.

The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 17,000 of the 49,000 delay minutes reported here.

Cancellations run at 2.91%, against 1.81% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

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. 12.5% 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 1,598 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 75.0% on time across 2,237 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.

The sample behind these figures is 2,232 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 JFK to SJU

Put together: the delay figures matter less here than the 2.91% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,164 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