Airport month record
MIADEC
Miami International in December 2025
- Departures
- 10,099
- Month
- December 2025
- National, same month
- 73.2%
- Carriers
- 9
Historical statistics for December 2025, not live status or a forecast for this year’s December. For today’s conditions at MIA, see live FAA status.
MIA in December sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points better than the national rate of 73.2%. The late ones land about an hour behind schedule. That rests on 10,099 flights, of which Envoy Air flew 1,512 at 83.3% on time.
Envoy Air is the most reliable of the six carriers covered here at 83.3% on time across 1,512 flights.
Key figures
On time
75.2%
Arrivals under 15 minutes late, of 9,951 completed departures
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.15%
Nationally in December: 1.55%
Whole year
73.8%
MIA across all twelve months
These figures cover 10,099 departures from Miami International in December 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
December next to MIA's other months
Against MIA's own year, December ran about a point better than the twelve-month rate of 73.8%, which makes it number eight of twelve months, best first. Either side of it, November ran 77.0% on time and January 76.0%, so this month sits in line with its neighbours.
| 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 (this page) | 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 December
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,251 flights86.8%
- 8am–11am1,484 flights85.7%
- 11am–2pm1,157 flights74.8%
- 2pm–5pm1,692 flights70.3%
- 5pm–8pm1,972 flights68.0%
- 8pm–5am2,543 flights72.4%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 86.8% of the time, against 68.0% for the evening window. That is 19 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 2,543 flights scheduled in it.
Across the week, Wednesday is the strongest day at 85.8% on time and Sunday the weakest at 65.1%. 21 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at MIA in December
The choice of carrier is not cosmetic here. Envoy Air arrives on time 83.3% of the time; Southwest Airlines manages 66.0%. Sample sizes sit next to every figure, because a two-point gap across 441 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 5,490 | 76.6% | 62 min | 0.29% | B+ |
| Envoy Air | 1,512 | 83.3% | 44 min | 0.93% | B+ |
| Delta Air Lines | 1,068 | 67.3% | 87 min | 3.65% | C− |
| United Airlines | 659 | 76.2% | 72 min | 0.30% | B+ |
| Southwest Airlines | 441 | 66.0% | 52 min | 1.13% | C |
| Frontier Airlines | 392 | 70.0% | 85 min | 4.85% | C− |
| Spirit Airlinesthin sample | 363 | 61.7% | 75 min | 5.51% | D− |
| Republic Airwaysthin sample | 97 | 64.6% | 90 min | 1.03% | D |
| Alaska Airlinesthin sample | 77 | 70.3% | 58 min | 0.00% | C+ |
Frontier Airlines cancels 4.8% 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 in December
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| MIA to ATL · Atlanta | 584 | 76.0% | 73 min | 2.40% | B |
| MIA to LGA · New York | 532 | 66.2% | 67 min | 3.95% | C− |
| MIA to DFW · Dallas-Fort Worth | 401 | 80.9% | 63 min | 0.75% | B+ |
| MIA to EWR · Newark | 393 | 68.7% | 73 min | 2.29% | C |
| MIA to JFK · New York | 392 | 65.5% | 74 min | 3.57% | C− |
| MIA to ORD · Chicago | 383 | 74.3% | 59 min | 1.31% | C |
| MIA to CLT · Charlottethin sample | 353 | 78.3% | 60 min | 0.57% | B+ |
| MIA to DCA · Washingtonthin sample | 344 | 76.4% | 59 min | 0.29% | B+ |
| MIA to IAH · Houstonthin sample | 340 | 82.2% | 56 min | 0.00% | B+ |
| MIA to MCO · Orlandothin sample | 331 | 80.3% | 72 min | 0.30% | B+ |
| MIA to TPA · Tampathin sample | 298 | 75.4% | 82 min | 0.34% | B+ |
| MIA to LAX · Los Angelesthin sample | 286 | 75.1% | 52 min | 0.00% | B+ |
| MIA to BOS · Bostonthin sample | 276 | 74.4% | 91 min | 2.17% | C |
| MIA to PHL · Philadelphiathin sample | 274 | 76.9% | 72 min | 2.19% | B |
| MIA to SJU · San Juanthin sample | 257 | 80.4% | 62 min | 0.78% | B+ |
| MIA to DEN · Denverthin sample | 241 | 74.6% | 52 min | 0.83% | C+ |
| MIA to BWI · Baltimorethin sample | 218 | 72.7% | 72 min | 0.92% | C+ |
| MIA to BNA · Nashvillethin sample | 213 | 74.6% | 47 min | 0.00% | C+ |
| MIA to RDU · Raleighthin sample | 188 | 69.5% | 54 min | 0.53% | C+ |
| MIA to AUS · Austinthin sample | 186 | 73.1% | 69 min | 0.00% | C+ |
| MIA to DTW · Detroitthin sample | 168 | 64.6% | 94 min | 2.38% | D |
| MIA to PHX · Phoenixthin sample | 160 | 75.6% | 49 min | 0.00% | B+ |
| MIA to SFO · San Franciscothin sample | 137 | 77.4% | 96 min | 0.00% | B+ |
| MIA to JAX · Jacksonvillethin sample | 135 | 74.8% | 42 min | 0.00% | C+ |
| MIA to LAS · Las Vegasthin sample | 134 | 80.5% | 78 min | 0.75% | B+ |
Delay causes
What held MIA up in December
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 162,000 reported delay minutes.
- 42%Late-arriving aircraft
- 37%Carrier
- 19%National Airspace System
- 2%Extreme weather
- 0%Security
42% 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 162,000 reported delay minutes here, that single category outweighs weather by 20 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 162,058 reported delay minutes.
Cancellations sit at 1.15% against a national 1.55%, which is ordinary. Diversions add another 0.32%.
8.0% of arrivals land an hour or more late, close to the national 10.0%. 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 December
For a December trip through MIA: expect 75.2% on time and 1.15% cancelled, going by December 2025. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- 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 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.