Route reliability record
BDL→SJU
Hartford to San Juan
- Flights
- 961
- Period
- July 2025 to June 2026
- Distance
- 1,666 mi
- Carriers
- 2
This route draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 961 BDL to SJU flights, with a median arrival 4 minutes late.
Best time to fly BDL to SJU: a 8am–11am departure, ideally on a Friday. Flights in that window arrived on time 70.7% of the time and Friday flights 69.6%, against 63.5% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 14 points behind the country as a whole. Across a thousand flights that is about 141 extra late arrivals.
Key figures
On time
63.5%
Arrivals under 15 minutes late, of 932 completed flights
Avg delay
95 min
Across delayed arrivals only, not all flights
Cancelled
1.87%
National rate is 1.81%
Best carrier
JetBlue
64.1% on time across 727 flights
These figures cover 961 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 BDL to SJU
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 727 | 64.1% | 90 min | 1.65% | D |
| Frontier Airlinesthin sample | 234 | 61.5% | 108 min | 2.56% | D |
Flight by flight
Flights on BDL to SJU
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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 19 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–8am95 flights68.1%
- 8am–11am329 flights70.7%
- 11am–2pm93 flights61.6%
- 2pm–5pm75 flights63.5%
- 5pm–8pm171 flights51.8%
- 8pm–5am198 flights60.6%
Scale runs 45% to 75%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 51.8% on time, against 70.7% for the 8am–11am 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 8am–11am window is the busiest, with 329 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 29 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.
February is the weak month at 44.9% on time, against 73.9% 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. December was the busiest month here, with 97 flights.
Across the week, Friday is the strongest day at 69.6% on time and Monday the weakest at 59.4%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 32,000 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.
- 44%Late-arriving aircraft
- 38%Carrier
- 17%National Airspace System
- 1%Extreme weather
44% 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 32,000 reported delay minutes here, that single category outweighs weather by 44 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 32,124 reported delay minutes.
The largest share of delay minutes, 38%, 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 12,000 of the 32,000 delay minutes reported here.
Cancellations sit at 1.87% against a national 1.81%, which is ordinary. Diversions add another 1.14%.
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.
At 1,666 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 70.9% on time across 961 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 961 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.
Work out the risk of missing a connection in SJU after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 961 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 63.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 932 completed flights over 12 months sit behind that.
Common questions
BDL to SJU questions
How often is BDL to SJU delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 36.5% of the 961 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is BDL to SJU compared with the rest of the country?
63.5% of flights arrive on time here against a national 77.6%, a difference of 14 points against it. That is worth a D on this site's grading scale.
What time of day has the fewest delays on BDL to SJU?
The 8am–11am departure window is the strongest at 70.7% on time. The 5pm–8pm window is the weakest at 51.8%, 19 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 February delays on BDL to SJU?
February is the weakest month at 44.9% on time, compared with 73.9% in May. Across the year that is 29 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
- SJU to BDL — the return legseparate record
- Luis Munoz Marin International (SJU) delay statistics
- JetBlue Airways on BDL to SJU64.1%
- Frontier Airlines on BDL to SJU61.5%
- BDL to ORD, a related route74.0%
- MCO to SJU, a related route73.0%
- BDL to ATL, a related route83.4%
- JetBlue Airways on-time record64.1%
- Frontier Airlines on-time record61.5%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. BDL to SJU and SJU to BDL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.