Carrier route record

B6SJU→JFK

JetBlue Airways · San Juan to New York

Flights: 2,237
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 SJU to JFK carries a cancellation problem, not just a delay problem: 3.2% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 2,237 flights, with a median arrival 5 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate JetBlue on SJU to JFK from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.0%

Arrivals under 15 minutes late, of 2,160 completed flights

Avg delay

78 min

Across delayed arrivals only, not all flights

Cancelled

3.22%

National rate is 1.81%

Whole route

79.3%

Every carrier on SJU to JFK, 3,657 flights

These figures cover 2,237 flights between July 2025 and June 2026. Beyond the headline rate, 10.3% 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 SJU to JFK

JetBlue flew 2,237 of the 3,657 flights on SJU to JFK, most of the route. Its 75.0% on time is 4 points worse than the route as a whole, which runs 79.3%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 88.8% to JetBlue at 75.0%. 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 SJU to JFK
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,104	88.8%	83 min	1.90%	A
Frontier Airlinesthin sample	316	76.1%	60 min	1.58%	B
JetBlue Airways (this page)	2,237	75.0%	78 min	3.22%	B−

Flight by flight

JetBlue flight numbers on SJU to JFK

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 14 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–8am426 flights83.8%
8am–11am295 flights81.2%
11am–2pm299 flights71.9%
2pm–5pm389 flights73.8%
5pm–8pm427 flights69.6%
8pm–5am401 flights69.8%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 83.8% of the time, against 69.6% for the evening window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 427 flights scheduled in it.

Across the year

JetBlue on SJU to JFK through the year

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

February is the weak month at 63.7% on time, against 86.9% in May. 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. July was the busiest month here, with 217 flights.

Across the week, Wednesday is the strongest day at 77.5% on time and Sunday the weakest at 71.2%. 6 points is a smaller lever than departure hour, but it is free.

Delay causes

Why JetBlue runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 42,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
47%
Carrier
41%
National Airspace System
12%
Extreme weather
0%
Security
0%

47% 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 42,000 reported delay minutes here, that single category outweighs weather by 47 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 42,297 reported delay minutes.

The largest share of delay minutes, 41%, 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 42,000 delay minutes reported here.

Cancellations run at 3.22%, against 1.81% nationally. That is about 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. 10.3% 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 69.5% on time across 2,232 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.

The sample behind these figures is 2,237 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 SJU to JFK

Put together: the delay figures matter less here than the 3.22% 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. 2,160 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