Airport month record

MIAMAY

Miami International in May 2026

Departures: 9,296
Month: May 2026
National, same month: 78.6%
Carriers: 8

Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at MIA, see live FAA status.

MIA in May sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 78.6%. The late ones land about an hour behind schedule. That rests on 9,296 flights, of which Envoy Air flew 1,204 at 85.0% on time.

Envoy Air is the most reliable of the five carriers covered here at 85.0% on time across 1,204 flights.

On time

75.3%

Arrivals under 15 minutes late, of 9,218 completed departures

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

0.45%

Nationally in May: 0.92%

Whole year

73.8%

MIA across all twelve months

These figures cover 9,296 departures from Miami International in May 2026. 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

May next to MIA's other months

Against MIA's own year, May ran 2 points better than the twelve-month rate of 73.8%, which makes it number seven of twelve months, best first. Cancellations were unusually low for MIA in May, at 0.45% against 1.62% across the year. Either side of it, April ran 75.3% on time and June 74.2%, so this month sits in line with its neighbours.

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	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 (this page)	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 May

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against 21 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,115 flights89.4%
8am–11am1,464 flights86.5%
11am–2pm889 flights82.0%
2pm–5pm1,725 flights71.1%
5pm–8pm1,843 flights65.6%
8pm–5am2,260 flights69.4%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.4% of the time, against 65.6% for the evening window. That is 24 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 2,260 flights scheduled in it.

Across the week, Wednesday is the strongest day at 80.7% on time and Sunday the weakest at 64.2%. 17 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at MIA in May

The choice of carrier is not cosmetic here. Envoy Air arrives on time 85.0% of the time; Southwest Airlines manages 64.4%. Sample sizes sit next to every figure, because a two-point gap across 515 flights means less than a ten-point one.

Carriers at MIA in May 2026
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	5,568	73.1%	71 min	0.45%	C+
Envoy Air	1,204	85.0%	39 min	0.00%	A+
Delta Air Lines	991	78.2%	62 min	1.11%	B
United Airlines	561	81.4%	64 min	0.53%	B+
Southwest Airlines	515	64.4%	53 min	0.19%	D+
Frontier Airlinesthin sample	347	74.9%	67 min	0.29%	C+
Republic Airwaysthin sample	68	73.1%	45 min	0.00%	C+
Alaska Airlinesthin sample	31	76.7%	40 min	3.23%	B−

The spread between Envoy and Southwest is 21 points, wide enough that it should decide the booking. On a hundred trips that is 21 more arrivals inside the on-time window.

Route by route

Busiest routes out of MIA in May

Routes from MIA in May 2026
Route	Flights	On time	Avg delay	Cancelled	Grade
MIA to ATL · Atlanta	552	73.4%	71 min	0.54%	C+
MIA to LGA · New York	458	72.6%	75 min	1.97%	C
MIA to DFW · Dallas-Fort Worth	398	74.2%	93 min	3.02%	C−
MIA to JFK · New York	398	76.8%	65 min	1.01%	B
MIA to ORD · Chicagothin sample	354	74.5%	73 min	0.56%	C+
MIA to DCA · Washingtonthin sample	339	80.6%	72 min	0.59%	B+
MIA to EWR · Newarkthin sample	315	81.4%	108 min	0.32%	B+
MIA to LAX · Los Angelesthin sample	304	76.7%	53 min	0.66%	B+
MIA to MCO · Orlandothin sample	303	72.6%	72 min	0.00%	C+
MIA to IAH · Houstonthin sample	294	74.6%	53 min	0.68%	C+
MIA to CLT · Charlottethin sample	294	78.8%	60 min	0.00%	B+
MIA to BOS · Bostonthin sample	280	77.4%	52 min	0.36%	B+
MIA to PHL · Philadelphiathin sample	247	79.2%	58 min	0.81%	B+
MIA to TPA · Tampathin sample	227	64.2%	87 min	0.00%	D+
MIA to BNA · Nashvillethin sample	226	62.8%	68 min	0.00%	D+
MIA to SJU · San Juanthin sample	214	85.5%	55 min	0.00%	A+
MIA to AUS · Austinthin sample	213	67.1%	74 min	0.00%	C+
MIA to BWI · Baltimorethin sample	204	75.5%	38 min	0.00%	B+
MIA to RDU · Raleighthin sample	202	76.2%	84 min	0.00%	B+
MIA to DEN · Denverthin sample	180	79.9%	51 min	0.00%	B+
MIA to PHX · Phoenixthin sample	173	85.0%	78 min	0.00%	A+
MIA to SFO · San Franciscothin sample	164	56.1%	53 min	0.00%	D+
MIA to LAS · Las Vegasthin sample	126	74.0%	72 min	0.00%	C+
MIA to MSY · New Orleansthin sample	124	66.9%	55 min	0.00%	C+
MIA to JAX · Jacksonvillethin sample	122	68.0%	61 min	0.00%	C+

Delay causes

What held MIA up in May

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 150,000 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
34%
National Airspace System
20%
Extreme weather
3%
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 150,000 reported delay minutes here, that single category outweighs weather by 15 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 149,771 reported delay minutes.

Cancellations are rare at 0.45%, below the national 0.92% 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.

8.4% of arrivals land an hour or more late, close to the national 7.1%. 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.

What to do with this

Flying from MIA in May

For a May trip through MIA: expect 75.3% on time and 0.45% cancelled, going by May 2026. The 5am–8am window was the strongest part of the day.

Miami International (MIA), the whole year
MIA in July63.6%
MIA in August67.6%
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 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