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DelayAtlas

Carrier route record

AAMIAJAX

American Airlines · Miami to Jacksonville

Flights
805
Period
July 2025 to June 2026
Share of route
53%
Carriers
3
C+GRADE

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

American on MIA to JAX draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 805 flights, with a median arrival 1 minute late.

The national on-time rate over the same period is 77.6%, so American on MIA to JAX runs 12 points behind the country as a whole. Across a thousand flights that is about 124 extra late arrivals.

Key figures

On time

65.2%

Arrivals under 15 minutes late, of 797 completed flights

Avg delay

67 min

Across delayed arrivals only, not all flights

Cancelled

0.99%

National rate is 1.81%

Whole route

74.1%

Every carrier on MIA to JAX, 1,526 flights

These figures cover 805 flights between July 2025 and June 2026. Beyond the headline rate, 12.2% 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

American against every carrier on MIA to JAX

American flew 805 of the 1,526 flights on MIA to JAX, most of the route. Its 65.2% on time is 9 points worse than the route as a whole, which runs 74.1%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Envoy at 84.3% to American at 65.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

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 MIA to JAX
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Air70184.3%49 min0.71%B+
Republic Airwaysthin sample2070.0%63 min0.00%C+
American Airlines (this page)80565.2%67 min0.99%C+

Departure window

When American runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 35 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–8am60 flights85.0%
  • 8am–11am60 flights91.7%
  • 11am–2pm1 flights
  • 2pm–5pm105 flights72.1%
  • 5pm–8pm135 flights56.5%
  • 8pm–5am444 flights59.9%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 56.5% on time, against 91.7% for the 8am–11am 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 8pm–5am window is the busiest, with 444 flights scheduled in it.

Across the year

American on MIA to JAX through the year

On-time rate by calendar month67J75F69M74A60M53J54J54A58S71O82N61D
Darker means more delays. Figures are on-time percentages.November best, June worst

June is the worst month at 52.6% on time, 29 points below November, the best at 81.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 89 flights.

Across the week, Wednesday is the strongest day at 76.1% on time and Sunday the weakest at 44.0%. 32 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week65.8Mon70.9Tue76.1Wed65.2Thu59.6Fri73.0Sat44.0Sun
Monday: 65.8 percent on time. Tuesday: 70.9 percent on time. Wednesday: 76.1 percent on time. Thursday: 65.2 percent on time. Friday: 59.6 percent on time. Saturday: 73.0 percent on time. Sunday: 44.0 percent on time

Delay causes

Why American runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 19,000 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
    47%
  • Carrier
    37%
  • National Airspace System
    11%
  • Extreme weather
    5%

47% 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 19,000 reported delay minutes here, that single category outweighs weather by 10 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 18,621 reported delay minutes.

The largest share of delay minutes, 37%, 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 6,946 of the 19,000 delay minutes reported here.

Cancellations sit at 0.99% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

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. 12.2% 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 335 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 80.2% on time across 803 flights, 15 points above 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 15 points of difference.

One caution: this is a thin sample. 805 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 American on MIA to JAX

Put together: treat all of this as provisional. 805 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 65.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 797 completed flights over 12 months sit behind that.

Related

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.