Carrier route record

B6FLL→BOS

JetBlue Airways · Fort Lauderdale to Boston

Flights: 1,952
Period: July 2025 to June 2026
Share of route: 57%
Carriers: 3

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

JetBlue on FLL to BOS draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 1,952 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 884 at 71.8% on time.

The national on-time rate over the same period is 77.6%, so JetBlue on FLL to BOS runs 12 points behind the country as a whole. Across a thousand flights that is about 120 extra late arrivals.

On time

65.6%

Arrivals under 15 minutes late, of 1,893 completed flights

Avg delay

78 min

Across delayed arrivals only, not all flights

Cancelled

2.92%

National rate is 1.81%

Whole route

66.5%

Every carrier on FLL to BOS, 3,406 flights

These figures cover 1,952 flights between July 2025 and June 2026. Beyond the headline rate, 16.2% 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 FLL to BOS

JetBlue flew 1,952 of the 3,406 flights on FLL to BOS, most of the route. Its 65.6% on time is about level with the route as a whole at 66.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 71.8% to Spirit at 61.7%.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 71.8% of the time; Spirit Airlines manages 61.7%. Sample sizes sit next to every figure, because a two-point gap across 570 flights means less than a ten-point one.

On-time performance by carrier on FLL to BOS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	884	71.8%	79 min	3.05%	C−
JetBlue Airways (this page)	1,952	65.6%	78 min	2.92%	C
Spirit Airlines	570	61.7%	77 min	4.74%	D−

Spirit Airlines cancels 4.7% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Flight by flight

JetBlue flight numbers on FLL to BOS

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 37 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am351 flights88.0%
8am–11am256 flights81.3%
11am–2pm308 flights56.6%
2pm–5pm341 flights58.0%
5pm–8pm323 flights51.0%
8pm–5am373 flights60.1%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 51.0% on time, against 88.0% 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 373 flights scheduled in it.

Across the year

JetBlue on FLL to BOS through the year

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

July is the worst month at 50.4% on time, 28 points below May, the best at 78.8%. 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 232 flights.

Across the week, Wednesday is the strongest day at 74.4% on time and Sunday the weakest at 57.7%. 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 51,000 reported delay minutes.

Late-arriving aircraft
39%
National Airspace System
30%
Carrier
27%
Extreme weather
4%
Security
1%

39% 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 51,000 reported delay minutes here, that single category outweighs weather by 10 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 50,722 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 88.0% on time here.

Cancellations run at 2.92%, 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. 16.2% 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.

The 1,237 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 66.1% on time across 1,961 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,952 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 FLL to BOS

Put together: the delay figures matter less here than the 2.92% 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. 1,893 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