Flight number record

B6 21

JetBlue Airways · Boston to West Palm Beach

Route: BOS → PBI
Departs: 07:00
Flights: 262
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s B6 21, check with JetBlue Airways.

B6 21 sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 262 flights, with a median arrival 4 minutes early.

The national on-time rate over the same period is 77.6%, so B6 21 runs 5 points behind the country as a whole. Across a thousand flights that is about 49 extra late arrivals.

On time

72.7%

Arrivals under 15 minutes late, of 253 completed flights

Avg delay

75 min

Across delayed arrivals only, not all flights

Cancelled

3.05%

National rate is 1.81%

1 hour+ late

12.3%

National rate is 8.1%

These figures cover 262 flights between July 2025 and June 2026. Beyond the headline rate, 12.3% 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.

Schedule

When B6 21 flies

B6 21 flies BOS to PBI without a single fixed slot. Its most common scheduled departure was 07:00, used on 48 of 262 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:0048 flights18.3%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and B6 21 runs 17 points worse at 72.7%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

B6 21 next to BOS to PBI

Every carrier on BOS to PBI combined arrived on time 65.7% of the time across 2,183 flights, so B6 21 is 7 points ahead of it. JetBlue flew 1,583 flights on the same city pair under all its flight numbers, including this one, and those ran 64.0% on time. Across its whole network JetBlue Airways managed 72.7%, close to this flight's figure.

B6 21 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
B6 21thin sample	262	72.7%	75 min	3.05%	C−
All JetBlue Airways on BOS–PBI	1,583	64.0%	71 min	3.28%	D−
All carriers on BOS–PBI	2,183	65.7%	72 min	3.02%	C−
JetBlue Airways, whole network	234,468	72.7%	76 min	2.56%	C

Across the year

B6 21 quarter by quarter

B6 21 did not run the same all year. Its best quarter was Apr–Jun 2026 at 96.2% on time and its weakest Oct–Dec 2025 at 70.1%, a swing of 26 points on roughly 87 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Jul–Sep 202592 flights72.4%
Oct–Dec 202590 flights70.1%
Jan–Mar 202628 flights—
Apr–Jun 202652 flights96.2%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, B6 21 did best on Tuesday at 85.3% on time and worst on Saturday at 64.1%. Each day rests on about 37 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Delay causes

Why B6 21 runs late

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 5,163 reported delay minutes.

Late-arriving aircraft
39%
Carrier
31%
National Airspace System
30%
Extreme weather
0%
Security
0%

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 5,163 reported delay minutes here, that single category outweighs weather by 39 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 5,163 delay minutes reported on B6 21.

Cancellations run at 3.05%, 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 routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 12.3% 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.

The 1,197 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.

Every one of the 262 flights under B6 21 in the data flew BOS to PBI. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 262 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 B6 21

For a booking, the cancellation rate is the figure to plan around on B6 21: 3.05% of its 262 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.

Where to go next

A flight number here means JetBlue Airways’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

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