Airport month record

MIASEP

Miami International in September 2025

Departures: 7,573
Month: September 2025
National, same month: 83.4%
Carriers: 9

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at MIA, see live FAA status.

MIA in September lands a B+, 5 points worse than the national rate of 83.4%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 7,573 flights, of which Envoy Air flew 969 at 84.4% on time.

Envoy Air is the most reliable of the five carriers covered here at 84.4% on time across 969 flights.

On time

78.6%

Arrivals under 15 minutes late, of 7,523 completed departures

Avg delay

70 min

Across delayed arrivals only, not all flights

Cancelled

0.36%

Nationally in September: 0.51%

Whole year

73.8%

MIA across all twelve months

These figures cover 7,573 departures from Miami International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

September next to MIA's other months

Against MIA's own year, September ran 5 points better than the twelve-month rate of 73.8%, which makes it the best of the twelve months in the data. Cancellations were unusually low for MIA in September, at 0.36% against 1.62% across the year. Either side of it, August ran 67.6% on time and October 77.9%, so a trip moved by a few weeks would have landed in a worse stretch.

MIA month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	9,079	63.6%	84 min	2.60%	D
August 2025	8,731	67.6%	77 min	0.86%	C+
September 2025 (this page)	7,573	78.6%	70 min	0.36%	B+
October 2025	8,457	77.9%	70 min	0.37%	B+
November 2025	9,270	77.0%	67 min	1.95%	B
December 2025	10,099	75.2%	66 min	1.15%	B
January 2026	10,439	76.0%	77 min	5.01%	B−
February 2026	9,304	75.3%	64 min	1.74%	B
March 2026	10,460	69.6%	78 min	2.96%	C
April 2026	9,556	75.3%	62 min	0.30%	B+
May 2026	9,296	75.3%	66 min	0.45%	B+
June 2026	8,797	74.2%	72 min	0.78%	C+

Departure window

The best time of day to leave MIA in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am852 flights92.8%
8am–11am1,334 flights90.6%
11am–2pm801 flights84.0%
2pm–5pm1,257 flights67.6%
5pm–8pm1,600 flights68.2%
8pm–5am1,729 flights77.4%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.8% of the time, against 67.6% for the afternoon window. That is 25 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 1,729 flights scheduled in it.

Across the week, Saturday is the strongest day at 83.4% on time and Wednesday the weakest at 73.4%. 10 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at MIA in September

The choice of carrier is not cosmetic here. Envoy Air arrives on time 84.4% of the time; American Airlines manages 76.4%. Sample sizes sit next to every figure, because a two-point gap across 4,249 flights means less than a ten-point one.

Carriers at MIA in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	4,249	76.4%	67 min	0.61%	B+
Envoy Air	969	84.4%	59 min	0.00%	B+
Delta Air Lines	816	81.2%	84 min	0.00%	B+
United Airlines	410	79.7%	96 min	0.00%	B+
Southwest Airlines	366	81.4%	65 min	0.00%	B+
Spirit Airlinesthin sample	354	73.8%	79 min	0.28%	C+
Frontier Airlinesthin sample	284	84.9%	88 min	0.00%	B+
Republic Airwaysthin sample	91	83.5%	54 min	0.00%	B+
Alaska Airlinesthin sample	30	73.3%	46 min	0.00%	C+

Envoy leads American by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of MIA in September

Routes from MIA in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
MIA to LGA · New York	476	79.8%	73 min	0.21%	B+
MIA to ATL · Atlanta	419	78.0%	85 min	0.00%	B+
MIA to DFW · Dallas-Fort Worth	404	75.8%	76 min	3.22%	B−
MIA to JFK · New Yorkthin sample	360	85.4%	82 min	0.28%	A+
MIA to MCO · Orlandothin sample	347	78.6%	62 min	0.29%	B+
MIA to DCA · Washingtonthin sample	326	79.6%	57 min	0.61%	B+
MIA to ORD · Chicagothin sample	315	71.8%	64 min	0.00%	C+
MIA to EWR · Newarkthin sample	282	75.3%	86 min	0.35%	B+
MIA to CLT · Charlottethin sample	279	84.4%	71 min	0.72%	B+
MIA to IAH · Houstonthin sample	276	80.8%	96 min	0.00%	B+
MIA to BOS · Bostonthin sample	224	65.3%	67 min	0.00%	C+
MIA to PHL · Philadelphiathin sample	216	77.6%	62 min	0.93%	B+
MIA to LAX · Los Angelesthin sample	212	75.9%	105 min	0.00%	B+
MIA to TPA · Tampathin sample	202	80.1%	63 min	0.50%	B+
MIA to BNA · Nashvillethin sample	188	80.9%	81 min	0.00%	B+
MIA to RDU · Raleighthin sample	180	78.9%	70 min	0.00%	B+
MIA to SJU · San Juanthin sample	168	78.6%	84 min	0.00%	B+
MIA to DEN · Denverthin sample	158	77.8%	65 min	0.00%	B+
MIA to BWI · Baltimorethin sample	155	82.5%	57 min	0.00%	B+
MIA to AUS · Austinthin sample	125	79.8%	62 min	0.80%	B+
MIA to DTW · Detroitthin sample	120	83.3%	70 min	0.00%	B+
MIA to JAX · Jacksonvillethin sample	118	76.3%	55 min	0.00%	B+
MIA to LAS · Las Vegasthin sample	114	65.8%	72 min	0.00%	C+
MIA to MSY · New Orleansthin sample	110	76.4%	59 min	0.00%	B+
MIA to PHX · Phoenixthin sample	100	76.5%	39 min	0.00%	B+

Delay causes

What held MIA up in September

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 113,000 reported delay minutes.

Late-arriving aircraft
30%
Carrier
28%
Extreme weather
23%
National Airspace System
19%
Security
0%

Extreme weather accounts for 23% 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 comparison with the other months below is the more useful view of the risk. The national share is 6%, so this operation carries roughly 4.2 times the usual weather exposure. The split is drawn from 113,363 reported delay minutes.

Cancellations are rare at 0.36%, below the national 0.51% 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.

8.0% of arrivals land an hour or more late, close to the national 5.4%. 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 a little over an hour, which a normal layover absorbs.

What to do with this

Flying from MIA in September

For a September trip through MIA: this is one of the better months to be flying from here, 78.6% on time with 0.36% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

Miami International (MIA), the whole year
MIA in July63.6%
MIA in August67.6%
MIA in October77.9%
MIA in November77.0%
MIA in December75.2%
MIA in January76.0%
MIA in February75.3%
MIA in March69.6%
MIA in April75.3%
MIA in May75.3%
MIA in June74.2%

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