Airport month record

MIAAUG

Miami International in August 2025

Departures: 8,731
Month: August 2025
National, same month: 77.4%
Carriers: 10

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

MIA in August draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 8,731 flights, of which Envoy Air flew 960 at 77.3% on time.

Envoy Air is the most reliable of the six carriers covered here at 77.3% on time across 960 flights.

On time

67.6%

Arrivals under 15 minutes late, of 8,631 completed departures

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

0.86%

Nationally in August: 1.08%

Whole year

73.8%

MIA across all twelve months

These figures cover 8,731 departures from Miami International in August 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

August next to MIA's other months

Against MIA's own year, August ran 6 points worse than the twelve-month rate of 73.8%, which makes it number eleven of twelve months, best first. Cancellations were unusually low for MIA in August, at 0.86% against 1.62% across the year. Either side of it, July ran 63.6% on time and September 78.6%, so a trip moved by a few weeks would have landed in a better 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 (this page)	8,731	67.6%	77 min	0.86%	C+
September 2025	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 August

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 40 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am972 flights92.1%
8am–11am1,376 flights86.3%
11am–2pm1,087 flights72.2%
2pm–5pm1,455 flights56.1%
5pm–8pm1,553 flights52.2%
8pm–5am2,288 flights61.4%

Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 52.2% on time, against 92.1% 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. The 8pm–5am window is the busiest, with 2,288 flights scheduled in it.

Across the week, Wednesday is the strongest day at 79.1% on time and Saturday the weakest at 60.3%. 19 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at MIA in August

The choice of carrier is not cosmetic here. Envoy Air arrives on time 77.3% of the time; American Airlines manages 64.3%. Sample sizes sit next to every figure, because a two-point gap across 5,121 flights means less than a ten-point one.

Carriers at MIA in August 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	5,121	64.3%	76 min	0.92%	D+
Envoy Air	960	77.3%	48 min	0.00%	B+
Delta Air Lines	877	72.2%	88 min	1.37%	C
United Airlines	470	69.2%	84 min	0.64%	C+
Southwest Airlines	391	70.7%	80 min	0.00%	C+
Spirit Airlines	381	68.4%	82 min	1.05%	C
Frontier Airlinesthin sample	335	72.8%	109 min	2.39%	C
Republic Airwaysthin sample	134	67.2%	85 min	0.00%	C+
JetBlue Airwaysthin sample	31	80.6%	33 min	0.00%	B+
Alaska Airlinesthin sample	31	43.3%	44 min	3.23%	F−

The spread between Envoy and American is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.

Route by route

Busiest routes out of MIA in August

Routes from MIA in August 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
MIA to ATL · Atlanta	499	64.2%	81 min	1.00%	D
MIA to LGA · New York	495	70.2%	83 min	1.41%	C
MIA to DFW · Dallas-Fort Worth	418	62.8%	69 min	3.11%	D−
MIA to JFK · New York	376	69.5%	97 min	1.33%	C
MIA to MCO · Orlandothin sample	357	62.4%	74 min	0.56%	D+
MIA to DCA · Washingtonthin sample	336	73.4%	67 min	0.60%	C+
MIA to ORD · Chicagothin sample	333	63.9%	76 min	1.80%	D
MIA to EWR · Newarkthin sample	305	69.2%	84 min	0.66%	C+
MIA to IAH · Houstonthin sample	300	67.0%	79 min	1.00%	C
MIA to CLT · Charlottethin sample	293	74.4%	81 min	1.37%	C
MIA to BOS · Bostonthin sample	287	70.2%	83 min	0.70%	C+
MIA to PHL · Philadelphiathin sample	268	74.9%	114 min	0.37%	C+
MIA to LAX · Los Angelesthin sample	252	74.2%	58 min	0.00%	C+
MIA to TPA · Tampathin sample	222	60.2%	101 min	0.45%	D+
MIA to SJU · San Juanthin sample	210	68.9%	95 min	0.48%	C+
MIA to BWI · Baltimorethin sample	197	64.9%	75 min	0.51%	D+
MIA to RDU · Raleighthin sample	196	59.1%	84 min	1.02%	D
MIA to BNA · Nashvillethin sample	189	70.2%	90 min	0.53%	C+
MIA to DEN · Denverthin sample	183	69.7%	87 min	0.55%	C+
MIA to AUS · Austinthin sample	157	69.0%	97 min	1.27%	C
MIA to LAS · Las Vegasthin sample	154	77.1%	55 min	0.65%	B+
MIA to SFO · San Franciscothin sample	142	70.9%	65 min	0.70%	C+
MIA to MSY · New Orleansthin sample	139	61.6%	66 min	0.72%	D+
MIA to DTW · Detroitthin sample	132	65.2%	55 min	0.00%	C+
MIA to JAX · Jacksonvillethin sample	131	67.2%	72 min	0.00%	C+

Delay causes

What held MIA up in August

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 214,000 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
43%
Carrier
30%
National Airspace System
20%
Extreme weather
7%
Security
0%

43% 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 214,000 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 214,138 reported delay minutes.

Cancellations are rare at 0.86%, below the national 1.08% 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.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.2% 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.

What to do with this

Flying from MIA in August

For a August trip through MIA: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 92.1% on time, and with 13.2% of arrivals an hour or more late, a connection here deserves more slack than the same trip in September would.

Miami International (MIA), the whole year
MIA in July63.6%
MIA in September78.6%
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