Carrier route record

F9MIA→JFK

Frontier Airlines · Miami to New York

Flights: 275
Period: July 2025 to June 2026
Share of route: 6%
Carriers: 3

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

Frontier on MIA to JFK lands a B, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 275 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,620 at 72.0% on time.

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

On time

80.7%

Arrivals under 15 minutes late, of 269 completed flights

Avg delay

107 min

Across delayed arrivals only, not all flights

Cancelled

2.18%

National rate is 1.81%

Whole route

71.9%

Every carrier on MIA to JFK, 4,555 flights

These figures cover 275 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% 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 MIA to JFK

Frontier flew 275 of the 4,555 flights on MIA to JFK, about 6% of it. Its 80.7% on time is 9 points better than the route as a whole, which runs 71.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Frontier at 80.7% to American at 70.9%.

The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on MIA to JFK
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlines (this page)thin sample	275	80.7%	107 min	2.18%	B
Delta Air Lines	1,620	72.0%	79 min	3.21%	C−
American Airlines	2,660	70.9%	82 min	2.67%	C

Delta Air Lines 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 matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am130 flights89.8%
8am–11am49 flights83.3%
11am–2pm—
2pm–5pm—
5pm–8pm—
8pm–5am96 flights66.7%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.8% of the time, against 66.7% for the overnight window. That is 23 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 130 flights scheduled in it.

Across the year

Frontier on MIA to JFK through the year

Jul–Sep 202591 flights90.0%
Oct–Dec 202590 flights71.3%
Jan–Mar 202681 flights79.7%
Apr–Jun 202613 flights—

Scale runs 65% to 95%. 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 80.7% on time across 275 flights.

Frontier on MIA to JFK did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.0% on time and its weakest Oct–Dec 2025 at 71.3%, a swing of 19 points on roughly 92 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 87.2% on time and Monday the weakest at 74.3%. 13 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 5,551 reported delay minutes.

Carrier
41%
Late-arriving aircraft
39%
Extreme weather
13%
National Airspace System
7%

Extreme weather accounts for 13% 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 2.2 times the usual weather exposure. The split is drawn from 5,551 reported delay minutes.

39% 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 5,551 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 2.18% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

8.9% 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 close to two hours, which a normal layover absorbs.

The 1,089 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 runs 79.4% on time across 274 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 275 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 MIA to JFK

Put together: treat all of this as provisional. 275 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 80.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 269 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