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DelayAtlas

Route reliability record

SJUBDL

San Juan to Hartford

Flights
961
Period
July 2025 to June 2026
Distance
1,666 mi
Carriers
2
CGRADE

This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 961 SJU to BDL flights, with a median arrival 3 minutes early.

Best time to fly SJU to BDL: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 83.0% of the time and Wednesday flights 78.0%, against 70.9% for the route overall.

The national on-time rate over the same period is 77.6%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 67 extra late arrivals.

Key figures

On time

70.9%

Arrivals under 15 minutes late, of 941 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

1.87%

National rate is 1.81%

Best carrier

JetBlue

69.3% on time across 726 flights

These figures cover 961 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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 SJU to BDL

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 BDL
AirlineFlightsOn timeAvg delayCancelledGrade
Frontier Airlinesthin sample23575.8%53 min1.70%B
JetBlue Airways72669.3%78 min1.93%C

Flight by flight

Flights on SJU to BDL

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 22 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–8am387 flights76.7%
  • 8am–11am47 flights83.0%
  • 11am–2pm70 flights70.0%
  • 2pm–5pm233 flights61.1%
  • 5pm–8pm172 flights66.9%
  • 8pm–5am52 flights75.0%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 83.0% of the time, against 61.1% for the afternoon window. That is 22 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 387 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 37 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.

On-time rate by calendar month68J59F71M71A88M81J67J65A61S51O73N79D
Darker means more delays. Figures are on-time percentages.May best, October worst

May is the best month on the calendar at 88.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 96 flights.

Across the week, Wednesday is the strongest day at 78.0% on time and Saturday the weakest at 67.9%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week70.9Mon71.1Tue78.0Wed69.8Thu71.0Fri67.9Sat68.3Sun
Monday: 70.9 percent on time. Tuesday: 71.1 percent on time. Wednesday: 78.0 percent on time. Thursday: 69.8 percent on time. Friday: 71.0 percent on time. Saturday: 67.9 percent on time. Sunday: 68.3 percent on time

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 20,000 reported delay minutes.

  • Carrier
    41%
  • Late-arriving aircraft
    37%
  • National Airspace System
    22%
  • Extreme weather
    1%

37% 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 20,000 reported delay minutes here, that single category outweighs weather by 37 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 20,019 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 8,158 of the 20,000 delay minutes reported here.

Cancellations sit at 1.87% against a national 1.81%, which is ordinary. Diversions add another 0.21%.

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. 10.1% 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 63.5% on time across 961 flights, 7 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 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 BDL 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 70.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 941 completed flights over 12 months sit behind that.

Common questions

SJU to BDL questions

How often is SJU to BDL 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 29.1% of the 961 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

How reliable is SJU to BDL compared with the rest of the country?

70.9% of flights arrive on time here against a national 77.6%, a difference of 7 points against it. That is worth a C on this site's grading scale.

What time of day has the fewest delays on SJU to BDL?

The 8am–11am departure window is the strongest at 83.0% on time. The 2pm–5pm window is the weakest at 61.1%, 22 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 October delays on SJU to BDL?

October is the weakest month at 50.9% on time, compared with 88.0% in May. Across the year that is 37 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

Direction matters. SJU to BDL and BDL to SJU are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed SJU to BDL’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.