Route profile
IAH→MIA
Flight reliability, delays and best times to fly from Houston to Miami, 964 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 20% of comparable major US routes (4,598 compared)
Calculated from 10,851 flights. How this is calculated
IAH → MIA arrives on time 75.4% of the time; the return trip, MIA → IAH, arrives on time 73.7% of the time.
IAH → MIA spends 29.4 minutes on the ground on a 964-mile trip: 18.9 minutes from pushback to wheels-up at IAH and 10.5 minutes from touchdown to gate at MIA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Why IAH → MIA flights are cancelled
July 2023 – July 2026
IAH → MIA cancelled 193 of 10,851 scheduled flights — about 1 in every 56. The reason filed most often was extreme weather, 63.2% of the cancellations coded on this route — about 1 in every 89 scheduled flights.
Share of cancellations
Of 193 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
122 cancellations, 63.2% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
51 cancellations, 26.4% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
20 cancellations, 10.4% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
193 coded cancellations were recorded on IAH → MIA; the section appears from 50.
When it goes wrong
July 2023 – July 2026
57 min late
against a median of 5 min early
IAH → MIA has an average that understates its risk: a typical arrival is 5 min early, but the worst tenth are 62 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 10,851 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at MIA after arriving from IAH.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 40% | Likely to miss |
| 45 min | 24% | High risk |
| 60 min | 16% | High risk |
| 90 min | 9.4% | Some risk |
| 120 min | 6.4% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.78% of the time and diverts 0.34% of the time, which a late arrival never shows up in.
Chance of missing is the share of 10,621 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 57 minutes late (90th-percentile gate arrival delay), over 10,851 operations.
Any other layover length: connection checker.
Best time to fly
IAH → MIA flights departing 5–9 AM arrived on time 84.5% of the time, against 65.6% for 3–6 PM departures, a gap of 18.9 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 87.7% on time from 1,177 flights
- 6 AM: 81.5% on time from 201 flights
- 7 AM: 83.3% on time from 1,966 flights
- 8 AM: 81.2% on time from 168 flights
- 9 AM: 80.6% on time from 517 flights
- 10 AM: 78.3% on time from 353 flights
- 11 AM: 76.3% on time from 843 flights
- 12 PM: 74.8% on time from 1,373 flights
- 1 PM: too few flights to score
- 2 PM: 68.5% on time from 545 flights
- 3 PM: 70.7% on time from 125 flights
- 4 PM: 68.0% on time from 803 flights
- 5 PM: 59.8% on time from 453 flights
- 6 PM: 67.1% on time from 1,715 flights
- 7 PM: 69.8% on time from 229 flights
- 8 PM: 64.1% on time from 235 flights
- 9 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAH → MIA runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for IAH → MIA. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on IAH → MIA, at 38.3%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 84.5% of the time and 3–6 PM departures 65.6%.
How this route holds up in bad weather
July 2023 – July 2026
Bad weather raises cancellations by a similar amount at both ends of IAH to MIA: 3.4 times the normal rate at IAH and 3.3 times at MIA. Cancelled in bad weather against normal hours: IAH 4.1% against 1.2%, MIA 4.5% against 1.3%. Flights that did leave MIA in bad weather arrived on time 50.6% of the time, against 74.1% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | IAH | MIA |
|---|---|---|
| Cancelled in bad weather | 4.1% | 4.5% |
| Cancelled in normal hours | 1.2% | 1.3% |
| Arrived on time, bad weather | 63.8% | 50.6% |
| Arrived on time, normal hours | 78.6% | 74.1% |
| Departures in bad weather | 28,922 | 15,746 |
Of the carriers on this route, United Airlines (3.4% cancelled against 5.2% for the other carriers at IAH) cancelled the fewest departures from IAH in bad weather and Frontier Airlines (5.0% cancelled against 3.8% for the other carriers at IAH) the most. One more carrier flies this route but has too few bad-weather departures from IAH to compare.
This route’s airlines in bad weather at IAH
All departures from IAH| Airline | Bad-weather departures | Cancelled | Other carriers |
|---|---|---|---|
| United Airlines | 17,078 | 3.4%below the others | 5.2% |
| Spirit Airlines | 2,056 | 4.3%about level | 4.4% |
| American Airlines | 2,079 | 4.6%about level | 3.9% |
| Frontier Airlines | 915 | 5.0%above the others | 3.8% |
These are airport figures, not route figures: every scheduled departure from IAH and MIA, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from IAH on every route.
Weather source and limits. In full: IAH (airlines), MIA, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| American Airlines | 4,330 | 75.6% | 1.82% | -6 min | 9.8% |
| United Airlines | 4,204 | 76.8% | 1.40% | -5 min | 8.3% |
| Spirit Airlines | 1,500 | 73.9% | 2.73% | -7 min | 10.9% |
| Envoy Air | 534 | 73.3% | 0.56% | -7 min | 8.9% |
| Frontier Airlines | 269 | 63.6% | 4.09% | 0 min | 17.4% |
American Airlines flew 40.0% of the 10,837 flights listed. Frontier Airlines cancelled 4.09% of its flights here against 0.56% for Envoy Air.
United Airlines arrived on time 13.2 percentage points more often than Frontier Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AA1347 American Airlines | 7:20 AM | 1,079 | 79.2% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 9.6 percentage points.
By month
- Jan: 76.7%
- Feb: 78.3%
- Mar: 70.2%
- Apr: 81.1%
- May: 68.7%
- Jun: 70.4%
- Jul: 67.5%
- Aug: 74.9%
- Sep: 79.4%
- Oct: 83.2%
- Nov: 82.7%
- Dec: 75.9%
July is historically the weakest month and October the strongest, a spread of 15.7 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 73.6% from 302 flights
- August 2023: 82.1% from 286 flights
- September 2023: 72.2% from 215 flights
- October 2023: 76.5% from 241 flights
- November 2023: 84.5% from 264 flights
- December 2023: 75.4% from 268 flights
- January 2024: 65.1% from 263 flights
- February 2024: 76.9% from 255 flights
- March 2024: 66.4% from 288 flights
- April 2024: 80.8% from 261 flights
- May 2024: 58.6% from 300 flights
- June 2024: 62.0% from 270 flights
- July 2024: 58.4% from 274 flights
- August 2024: 70.8% from 293 flights
- September 2024: 83.7% from 253 flights
- October 2024: 88.7% from 260 flights
- November 2024: 82.5% from 304 flights
- December 2024: 69.4% from 328 flights
- January 2025: 78.8% from 323 flights
- February 2025: 75.9% from 274 flights
- March 2025: 74.9% from 339 flights
- April 2025: 82.0% from 314 flights
- May 2025: 70.2% from 347 flights
- June 2025: 73.5% from 305 flights
- July 2025: 66.2% from 312 flights
- August 2025: 72.1% from 300 flights
- September 2025: 81.1% from 276 flights
- October 2025: 83.8% from 304 flights
- November 2025: 81.4% from 333 flights
- December 2025: 82.5% from 339 flights
- January 2026: 83.0% from 341 flights
- February 2026: 81.6% from 309 flights
- March 2026: 68.6% from 341 flights
- April 2026: 80.4% from 310 flights
- May 2026: 76.9% from 294 flights
- June 2026: 75.1% from 277 flights
- July 2026: 70.3% from 288 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 78.1% against 76.0% in the 12 months before — improving by 2.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 10,851 IAH → MIA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed