Carrier route record

F9SJU→JFK

Frontier Airlines · San Juan to New York

Flights: 316
Period: July 2025 to June 2026
Share of route: 9%
Carriers: 3

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

Frontier on SJU to JFK lands a B, 2 points worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 316 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,104 at 88.8% on time.

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

On time

76.1%

Arrivals under 15 minutes late, of 309 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.58%

National rate is 1.81%

Whole route

79.3%

Every carrier on SJU to JFK, 3,657 flights

These figures cover 316 flights between July 2025 and June 2026. Beyond the headline rate, 8.7% 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

Frontier against every carrier on SJU to JFK

Frontier flew 316 of the 3,657 flights on SJU to JFK, about 9% of it. Its 76.1% on time is 3 points worse than the route as a whole, which runs 79.3%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 88.8% to JetBlue at 75.0%.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 88.8% of the time; JetBlue Airways manages 75.0%. Sample sizes sit next to every figure, because a two-point gap across 2,237 flights means less than a ten-point one.

On-time performance by carrier on SJU to JFK
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,104	88.8%	83 min	1.90%	A
Frontier Airlines (this page)thin sample	316	76.1%	60 min	1.58%	B
JetBlue Airways	2,237	75.0%	78 min	3.22%	B−

JetBlue Airways cancels 3.2% 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

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 316 flights.

5am–8am108 flights78.5%
8am–11am95 flights79.8%
11am–2pm15 flights—
2pm–5pm—
5pm–8pm—
8pm–5am98 flights71.4%

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 79.8% of the time, against 71.4% for the overnight window. That is 8 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 108 flights scheduled in it.

Across the year

Frontier on SJU to JFK through the year

Jul–Sep 2025140 flights69.3%
Oct–Dec 202592 flights85.4%
Jan–Mar 202671 flights77.6%
Apr–Jun 202613 flights—

Scale runs 60% to 90%. 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 76.1% on time across 316 flights.

Frontier on SJU to JFK did not run the same all year. Its best quarter was Oct–Dec 2025 at 85.4% on time and its weakest Jul–Sep 2025 at 69.3%, a swing of 16 points on roughly 105 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.

Across the week, Friday is the strongest day at 86.7% on time and Monday the weakest at 66.7%. 20 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 4,417 reported delay minutes.

National Airspace System
34%
Carrier
31%
Late-arriving aircraft
20%
Extreme weather
14%

Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.3 times the usual weather exposure. The split is drawn from 4,417 reported delay minutes.

34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,512 minutes out of 4,417, against a national NAS share of 21%.

Cancellations sit at 1.58% against a national 1.81%, which is ordinary. Diversions add another 0.63%.

Connections and stage length

What a delay here costs

8.7% 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 about an hour, which a normal layover absorbs.

At 1,598 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 56.1% on time across 315 flights, 20 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 20 points of difference.

One caution: this is a thin sample. 316 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 JFK

Put together: treat all of this as provisional. 316 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 76.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 309 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