Route reliability record
MIA→JAX
Miami to Jacksonville
- Flights
- 1,526
- Period
- July 2025 to June 2026
- Distance
- 335 mi
- Carriers
- 3
This route sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,526 MIA to JAX flights, of which Envoy Air flew 701 at 84.3% on time.
Best time to fly MIA to JAX: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 94.8% of the time and Tuesday flights 79.7%, against 74.1% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.1%
Arrivals under 15 minutes late, of 1,512 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.85%
National rate is 1.81%
Best carrier
Envoy
84.3% on time across 701 flights
These figures cover 1,526 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% 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
Which airline is most reliable on MIA to JAX
The choice of carrier is not cosmetic here. Envoy Air arrives on time 84.3% of the time; American Airlines manages 65.2%. Sample sizes sit next to every figure, because a two-point gap across 805 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 701 | 84.3% | 49 min | 0.71% | B+ |
| Republic Airwaysthin sample | 20 | 70.0% | 63 min | 0.00% | C+ |
| American Airlines | 805 | 65.2% | 67 min | 0.99% | C+ |
The spread between Envoy and American is 19 points, wide enough that it should decide the booking. On a hundred trips that is 19 more arrivals inside the on-time window.
Best ways to make this trip
The most reliable ways to fly Miami to Jacksonville
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. MIA → JAXMiami to Jacksonville | Envoy Air | 83.7% | 84.3% | 0.71% | 8am–11am, Mon | — |
| 2. MIA → JAXMiami to Jacksonville | American Airlines | 64.6% | 65.2% | 0.99% | 8am–11am, Wed | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 19 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am60 flights85.0%
- 8am–11am289 flights94.8%
- 11am–2pm71 flights83.1%
- 2pm–5pm202 flights69.3%
- 5pm–8pm339 flights72.5%
- 8pm–5am565 flights63.7%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.7% on time, against 94.8% 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 565 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 65.1% on time, 22 points below November, the best at 86.6%. 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. July was the busiest month here, with 156 flights.
Across the week, Tuesday is the strongest day at 79.7% on time and Sunday the weakest at 62.1%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 24,000 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.
- 45%Late-arriving aircraft
- 32%Carrier
- 15%National Airspace System
- 8%Extreme weather
45% 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 24,000 reported delay minutes here, that single category outweighs weather by 6 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 24,335 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 94.8% on time here.
Cancellations are rare at 0.85%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
8.3% 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 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 80.5% on time across 1,525 flights, 6 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 6 points of difference.
The sample behind these figures is 1,526 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in JAX after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 86.6% on time and July 65.1%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 1,512 completed flights over 12 months sit behind that.
Common questions
MIA to JAX questions
How often is MIA to JAX delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.9% of the 1,526 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on MIA to JAX?
Envoy Air leads at 84.3% on time across 701 flights. American Airlines is at the other end on 65.2%, a gap of 19 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on MIA to JAX?
The 8am–11am departure window is the strongest at 94.8% on time. The 8pm–5am window is the weakest at 63.7%, 31 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on MIA to JAX?
July is the weakest month at 65.1% on time, compared with 86.6% in November. Across the year that is 22 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- JAX to MIA — the return legseparate record
- Miami International (MIA) delay statistics
- Envoy Air on MIA to JAX84.3%
- American Airlines on MIA to JAX65.2%
- MIA to ATL, a related route73.7%
- ATL to JAX, a related route75.5%
- MIA to LGA, a related route68.0%
- Envoy Air on-time record84.3%
- Republic Airways on-time record70.0%
- American Airlines on-time record65.2%
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
Direction matters. MIA to JAX and JAX to MIA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.