Route reliability record
BOS→PBI
Boston to West Palm Beach
- Flights
- 2,183
- Period
- July 2025 to June 2026
- Distance
- 1,197 mi
- Carriers
- 3
This route draws a C−. About one flight in three arrive 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 2,183 flights, of which Delta Air Lines flew 591 at 70.7% on time.
The national on-time rate over the same period is 77.6%, so this route runs 12 points behind the country as a whole. Across a thousand flights that is about 119 extra late arrivals.
Key figures
On time
65.7%
Arrivals under 15 minutes late, of 2,108 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
3.02%
National rate is 1.81%
Best carrier
Delta
70.7% on time across 591 flights
These figures cover 2,183 flights between July 2025 and June 2026. Beyond the headline rate, 14.4% 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
Which airline is most reliable on BOS to PBI
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 70.7% of the time; JetBlue Airways manages 64.0%. Sample sizes sit next to every figure, because a two-point gap across 1,583 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 591 | 70.7% | 74 min | 2.37% | C |
| JetBlue Airways | 1,583 | 64.0% | 71 min | 3.28% | D− |
| American Airlinesthin sample | 9 | 55.6% | 162 min | 0.00% | D+ |
JetBlue Airways cancels 3.3% 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.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am415 flights78.8%
- 8am–11am347 flights78.8%
- 11am–2pm270 flights65.8%
- 2pm–5pm696 flights57.6%
- 5pm–8pm245 flights57.0%
- 8pm–5am210 flights56.2%
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 56.2% on time, against 78.8% 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 2pm–5pm window is the busiest, with 696 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 25 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 53.6% on time, against 78.5% 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. March was the busiest month here, with 248 flights.
Across the week, Wednesday is the strongest day at 74.3% on time and Sunday the weakest at 54.7%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 52,000 reported delay minutes.
- 39%Late-arriving aircraft
- 28%National Airspace System
- 28%Carrier
- 4%Extreme weather
- 0%Security
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 52,000 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 51,853 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 78.8% on time here.
Cancellations run at 3.02%, 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 actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.4% 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.
The return leg runs 66.1% on time across 2,181 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 2,183 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 this route
Put together: the delay figures matter less here than the 3.02% 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. 2,108 completed flights over 12 months sit behind that.
Common questions
BOS to PBI questions
How often is BOS to PBI delayed?
About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 34.3% of the 2,183 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on BOS to PBI?
Delta Air Lines leads at 70.7% on time across 591 flights. JetBlue Airways is at the other end on 64.0%, a gap of 7 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on BOS to PBI?
The 5am–8am departure window is the strongest at 78.8% on time. The 8pm–5am window is the weakest at 56.2%, 23 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on BOS to PBI?
December is the weakest month at 53.6% on time, compared with 78.5% in May. Across the year that is 25 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- PBI to BOS — the return legseparate record
- Boston Logan International (BOS) delay statistics
- Delta Air Lines on-time record70.7%
- JetBlue Airways on-time record64.0%
- American Airlines on-time record55.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BOS to PBI and PBI to BOS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.