Miami, FL · departure reliability
MIA
Miami International
- Departures
- 111,095
- Period
- June 2025 to May 2026
- Carriers
- 9
- US rank
- #20 by volume
Miami
Miami International 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 77.4%. The late ones land a little over an hour behind schedule. That rests on 111,095 flights, of which Envoy Air flew 13,572 at 82.7% on time.
Envoy Air is the most reliable of the nine carriers covered here at 82.7% on time across 13,572 flights.
Key figures
On time
73.4%
Departures arriving under 15 minutes late at their destination
Avg delay
73 min
Across delayed flights only
Cancelled
1.69%
National rate is 1.80%
Best carrier
Envoy
82.7% on time here
These figures cover 111,000 flights between June 2025 and May 2026. Beyond the headline rate, 9.9% 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
Which airlines run best out of MIA
The choice of carrier is not cosmetic here. Envoy Air arrives on time 82.7% of the time; Spirit Airlines manages 66.2%. Sample sizes sit next to every figure, because a two-point gap across 3,864 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 63,838 | 71.6% | 73 min | 1.69% | C |
| Envoy Air | 13,572 | 82.7% | 49 min | 0.95% | B+ |
| Delta Air Lines | 11,630 | 72.8% | 82 min | 2.10% | C |
| United Airlines | 6,812 | 77.8% | 84 min | 1.01% | B |
| Southwest Airlines | 5,287 | 72.6% | 60 min | 1.19% | C |
| Frontier Airlines | 4,250 | 74.3% | 86 min | 2.21% | C |
| Spirit Airlines | 3,864 | 66.2% | 79 min | 4.35% | C− |
| Republic Airways | 1,145 | 67.3% | 95 min | 1.31% | C |
| Alaska Airlines | 533 | 68.7% | 57 min | 1.50% | C |
Spirit Airlines cancels 4.3% 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.
Route by route
Busiest routes out of MIA
Route-level records vary far more than the airport average. These are the 25 busiest departures from MIA, each with its own on-time rate against the airport-wide 73.4%.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| MIA to ATL · Atlanta | 6,240 | 72.6% | 84 min | 1.51% | C |
| MIA to LGA · New York | 6,036 | 67.4% | 77 min | 4.19% | C− |
| MIA to DFW · Dallas-Fort Worth | 4,836 | 72.6% | 80 min | 2.69% | C |
| MIA to JFK · New York | 4,608 | 71.1% | 80 min | 2.99% | C |
| MIA to ORD · Chicago | 4,451 | 70.8% | 74 min | 1.82% | C |
| MIA to EWR · Newark | 3,977 | 71.7% | 84 min | 2.77% | C |
| MIA to DCA · Washington | 3,962 | 74.5% | 70 min | 2.27% | C |
| MIA to MCO · Orlando | 3,841 | 71.9% | 73 min | 1.07% | C |
| MIA to IAH · Houston | 3,764 | 76.4% | 82 min | 1.30% | B |
| MIA to CLT · Charlotte | 3,729 | 77.5% | 75 min | 1.77% | B |
| MIA to BOS · Boston | 3,451 | 69.4% | 75 min | 2.46% | C |
| MIA to LAX · Los Angeles | 3,247 | 74.9% | 71 min | 0.59% | C+ |
| MIA to PHL · Philadelphia | 3,096 | 75.2% | 80 min | 2.10% | B |
| MIA to TPA · Tampa | 2,942 | 70.1% | 79 min | 1.19% | C |
| MIA to SJU · San Juan | 2,629 | 74.0% | 77 min | 1.14% | C |
| MIA to DEN · Denver | 2,510 | 77.5% | 69 min | 0.56% | B+ |
| MIA to BNA · Nashville | 2,471 | 72.1% | 70 min | 1.25% | C |
| MIA to RDU · Raleigh | 2,370 | 70.8% | 75 min | 1.65% | C |
| MIA to BWI · Baltimore | 2,301 | 73.9% | 64 min | 2.22% | C |
| MIA to AUS · Austin | 2,131 | 73.2% | 72 min | 1.13% | C |
| MIA to PHX · Phoenix | 1,834 | 77.9% | 64 min | 0.76% | B+ |
| MIA to DTW · Detroit | 1,830 | 72.8% | 73 min | 1.48% | C |
| MIA to SFO · San Francisco | 1,701 | 73.5% | 65 min | 0.65% | C+ |
| MIA to JAX · Jacksonville | 1,560 | 73.4% | 67 min | 0.96% | C+ |
| MIA to MSY · New Orleans | 1,546 | 71.9% | 64 min | 1.62% | C |
Departure window
The best time of day to leave MIA
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am13,315 flights89.6%
- 8am–11am16,859 flights86.0%
- 11am–2pm12,646 flights74.3%
- 2pm–5pm19,540 flights67.6%
- 5pm–8pm21,910 flights64.6%
- 8pm–5am26,825 flights68.1%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.6% on time, against 89.6% 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.
Across the year
When MIA runs late
MIA's year swings by 15 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 63.6% on time, 15 points below September, the best at 78.6%. 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.
Across the week, Tuesday is the strongest day at 78.9% on time and Sunday the weakest at 64.3%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why MIA gets delayed
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 2.11 million reported delay minutes.
- 41%Late-arriving aircraft
- 32%Carrier
- 21%National Airspace System
- 5%Extreme weather
- 0%Security
41% 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 2.11 million reported delay minutes here, that single category outweighs weather by 8 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 practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.6% on time here.
Cancellations sit at 1.69% against a national 1.80%, which is ordinary. Diversions add another 0.36%.
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.9% of arrivals land a full hour or more behind schedule, against 8.2% 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.
111,095 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
What to do with this
Flying out of MIA
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 78.6% on time and July 63.6%, a swing of 15 points. If the dates move at all, move them out of July before you think about anything else.
Common questions
MIA delay questions
How often is Miami (MIA) delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 26.6% of the 111,095 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on Miami (MIA)?
Envoy Air leads at 82.7% on time across 13,572 flights. Spirit Airlines is at the other end on 66.2%, a gap of 17 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 Miami (MIA)?
The 5am–8am departure window is the strongest at 89.6% on time. The 5pm–8pm window is the weakest at 64.6%, 25 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 Miami (MIA)?
July is the weakest month at 63.6% on time, compared with 78.6% in September. Across the year that is 15 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
- MIA to ATL — Atlanta72.6%
- MIA to LGA — New York67.4%
- MIA to DFW — Dallas-Fort Worth72.6%
- MIA to JFK — New York71.1%
- MIA to ORD — Chicago70.8%
- American Airlines on-time record71.6%
- Envoy Air on-time record82.7%
- Delta Air Lines on-time record72.8%
- United Airlines on-time record77.8%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.