Carrier route record

F9SJU→BDL

Frontier Airlines · San Juan to Hartford

Flights: 235
Period: July 2025 to June 2026
Share of route: 24%
Carriers: 2

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

Frontier on SJU to BDL sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land roughly 55 minutes behind schedule. That rests on 235 flights, with a median arrival 11 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on SJU to BDL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.8%

Arrivals under 15 minutes late, of 231 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

1.70%

National rate is 1.81%

Whole route

70.9%

Every carrier on SJU to BDL, 961 flights

These figures cover 235 flights between July 2025 and June 2026. The median arrival is 11 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Frontier against every carrier on SJU to BDL

Frontier flew 235 of the 961 flights on SJU to BDL, about 24% of it. Its 75.8% on time is 5 points better than the route as a whole, which runs 70.9%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Frontier at 75.8% to JetBlue at 69.3%.

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
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlines (this page)thin sample	235	75.8%	53 min	1.70%	B
JetBlue Airways	726	69.3%	78 min	1.93%	C

Departure window

When Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 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–8am80 flights75.0%
8am–11am47 flights83.0%
11am–2pm11 flights—
2pm–5pm47 flights66.0%
5pm–8pm—
8pm–5am50 flights76.0%

Scale runs 60% 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 66.0% for the afternoon window. That is 17 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 80 flights scheduled in it.

Across the year

Frontier on SJU to BDL through the year

Jul–Sep 202557 flights70.9%
Oct–Dec 202527 flights—
Jan–Mar 202660 flights74.1%
Apr–Jun 202691 flights78.0%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 75.8% on time across 235 flights.

Quarter by quarter Frontier on SJU to BDL held fairly steady: 70.9% in Jul–Sep 2025, 74.1% in Jan–Mar 2026 and 78.0% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Saturday is the strongest day at 85.7% on time and Monday the weakest at 67.7%. 18 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier 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 2,975 reported delay minutes.

Carrier
40%
National Airspace System
32%
Late-arriving aircraft
28%

The largest share of delay minutes, 40%, 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 1,194 of the 2,975 delay minutes reported here. The split is drawn from 2,975 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 83.0% on time here.

Cancellations sit at 1.70% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

7.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 55 minutes, which a normal layover absorbs.

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 61.5% on time across 234 flights, 14 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 14 points of difference.

One caution: this is a thin sample. 235 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 Frontier on SJU to BDL

Put together: treat all of this as provisional. 235 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 75.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 231 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