Carrier route record

F9MCO→ISP

Frontier Airlines · Orlando to Islip

Flights: 376
Period: July 2025 to June 2026
Share of route: 26%
Carriers: 3

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

Frontier on MCO to ISP sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 376 flights. The strongest carrier on the route with a full sample, JetBlue Airways, flew 374 at 88.3% on time.

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

On time

75.1%

Arrivals under 15 minutes late, of 366 completed flights

Avg delay

81 min

Across delayed arrivals only, not all flights

Cancelled

2.39%

National rate is 1.81%

Whole route

74.8%

Every carrier on MCO to ISP, 1,427 flights

These figures cover 376 flights between July 2025 and June 2026. Beyond the headline rate, 10.4% 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

Frontier against every carrier on MCO to ISP

Frontier flew 376 of the 1,427 flights on MCO to ISP, about 26% of it. Its 75.1% on time is about level with the route as a whole at 74.8%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from JetBlue at 88.3% to Southwest at 67.1%.

The choice of carrier is not cosmetic here. JetBlue Airways arrives on time 88.3% of the time; Southwest Airlines manages 67.1%. Sample sizes sit next to every figure, because a two-point gap across 677 flights means less than a ten-point one.

On-time performance by carrier on MCO to ISP
Airline	Flights	On time	Avg delay	Cancelled	Grade
JetBlue Airways	374	88.3%	55 min	1.34%	A
Frontier Airlines (this page)	376	75.1%	81 min	2.39%	B
Southwest Airlines	677	67.1%	51 min	1.62%	C

The spread between JetBlue and Southwest is 21 points, wide enough that it should decide the booking. On a hundred trips that is 21 more arrivals inside the on-time window.

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 36 points, against 21 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am82 flights92.5%
8am–11am93 flights89.1%
11am–2pm27 flights—
2pm–5pm53 flights62.0%
5pm–8pm91 flights60.2%
8pm–5am30 flights56.7%

Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 56.7% on time, against 92.5% 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 8am–11am window is the busiest, with 93 flights scheduled in it.

Across the year

Frontier on MCO to ISP through the year

Jul–Sep 202599 flights64.9%
Oct–Dec 2025104 flights82.4%
Jan–Mar 202680 flights81.3%
Apr–Jun 202693 flights72.8%

Scale runs 55% 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 75.1% on time across 376 flights.

Frontier on MCO to ISP did not run the same all year. Its best quarter was Oct–Dec 2025 at 82.4% on time and its weakest Jul–Sep 2025 at 64.9%, a swing of 18 points on roughly 94 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, Tuesday is the strongest day at 92.3% on time and Sunday the weakest at 61.7%. 31 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 7,337 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.

Late-arriving aircraft
48%
Carrier
20%
Extreme weather
17%
National Airspace System
15%

Extreme weather accounts for 17% 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 2.8 times the usual weather exposure. The split is drawn from 7,337 reported delay minutes.

48% 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 7,337 reported delay minutes here, that single category outweighs weather by 3 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.

Cancellations sit at 2.39% against a national 1.81%, which is ordinary. Diversions add another 0.27%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.4% 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 971 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 is a different operation and performs like one: it runs 69.9% on time across 376 flights, 5 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 5 points of difference.

One caution: this is a thin sample. 376 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 MCO to ISP

Put together: treat all of this as provisional. 376 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 75.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 366 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