Route profile
MIA→IAH
Flight reliability, delays and best times to fly from Miami to Houston, 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 16% of comparable major US routes (4,598 compared)
Calculated from 10,858 flights. How this is calculated
MIA → IAH arrives on time 73.7% of the time; the return trip, IAH → MIA, arrives on time 75.4% of the time.
MIA → IAH spends 31.8 minutes on the ground on a 964-mile trip: 21.6 minutes from pushback to wheels-up at MIA and 10.2 minutes from touchdown to gate at IAH.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Why MIA → IAH flights are cancelled
July 2023 – July 2026
MIA → IAH cancelled 190 of 10,858 scheduled flights — about 1 in every 57. The reason filed most often was extreme weather, 62.1% of the cancellations coded on this route — about 1 in every 92 scheduled flights.
Share of cancellations
Of 190 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.
118 cancellations, 62.1% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
52 cancellations, 27.4% 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, 10.5% 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.
190 coded cancellations were recorded on MIA → IAH; the section appears from 50.
When it goes wrong
July 2023 – July 2026
61 min late
against a median of 5 min early
MIA → IAH has an average that understates its risk: a typical arrival is 5 min early, but the worst tenth are 66 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 10,858 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAH after arriving from MIA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 41% | Likely to miss |
| 45 min | 25% | High risk |
| 60 min | 18% | High risk |
| 90 min | 10% | 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 1.75% of the time and diverts 0.23% of the time, which a late arrival never shows up in.
Chance of missing is the share of 10,643 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 61 minutes late (90th-percentile gate arrival delay), over 10,858 operations.
Any other layover length: connection checker.
Best time to fly
MIA → IAH flights departing 5–9 AM arrived on time 89.3% of the time, against 61.8% for 3–6 PM departures, a gap of 27.5 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 93.6% on time from 863 flights
- 7 AM: 88.9% on time from 589 flights
- 8 AM: 86.5% on time from 1,180 flights
- 9 AM: 86.8% on time from 493 flights
- 10 AM: 80.6% on time from 235 flights
- 11 AM: 82.0% on time from 351 flights
- 12 PM: 79.0% on time from 594 flights
- 1 PM: 82.5% on time from 676 flights
- 2 PM: 67.9% on time from 554 flights
- 3 PM: 61.0% on time from 873 flights
- 4 PM: 64.6% on time from 824 flights
- 5 PM: 58.9% on time from 537 flights
- 6 PM: 61.8% on time from 630 flights
- 7 PM: 66.8% on time from 712 flights
- 8 PM: 57.6% on time from 213 flights
- 9 PM: 62.7% on time from 700 flights
- 10 PM: 61.9% on time from 756 flights
- 11 PM: too few flights to score
Why MIA → IAH 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 MIA → IAH. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on MIA → IAH, at 38.1%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 89.3% of the time and 3–6 PM departures 61.8%.
How this route holds up in bad weather
July 2023 – July 2026
Bad weather raises cancellations by a similar amount at both ends of MIA to IAH: 3.3 times the normal rate at MIA and 3.4 times at IAH. Cancelled in bad weather against normal hours: MIA 4.5% against 1.3%, IAH 4.1% against 1.2%. 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 | MIA | IAH |
|---|---|---|
| Cancelled in bad weather | 4.5% | 4.1% |
| Cancelled in normal hours | 1.3% | 1.2% |
| Arrived on time, bad weather | 50.6% | 63.8% |
| Arrived on time, normal hours | 74.1% | 78.6% |
| Departures in bad weather | 15,746 | 28,922 |
Of the carriers on this route, United Airlines (2.4% cancelled against 4.4% for the other carriers at MIA) cancelled the fewest departures from MIA in bad weather and Envoy Air (6.4% cancelled against 4.4% for the other carriers at MIA) the most.
This route’s airlines in bad weather at MIA
All departures from MIA| Airline | Bad-weather departures | Cancelled | Other carriers |
|---|---|---|---|
| United Airlines | 1,004 | 2.4%below the others | 4.4% |
| Frontier Airlines | 557 | 3.9%about level | 4.2% |
| Spirit Airlines | 766 | 4.8%about level | 4.4% |
| American Airlines | 8,534 | 5.4%above the others | 4.2% |
| Envoy Air | 1,840 | 6.4%above the others | 4.4% |
These are airport figures, not route figures: every scheduled departure from MIA and IAH, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from MIA on every route.
Weather source and limits. In full: MIA (airlines), IAH, 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 | 4,334 | 67.2% | 1.68% | -1 min | 12.4% |
| United Airlines | 4,202 | 80.2% | 1.59% | -9 min | 7.9% |
| Spirit Airlines | 1,504 | 72.1% | 2.46% | -4 min | 12.7% |
| Envoy Air | 534 | 80.3% | 0.56% | -5 min | 5.9% |
| Frontier Airlines | 270 | 73.8% | 3.70% | -12 min | 11.9% |
American Airlines flew 40.0% of the 10,844 flights listed. Frontier Airlines cancelled 3.70% of its flights here against 0.56% for Envoy Air.
Envoy Air arrived on time 13.1 percentage points more often than American Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 10.2 percentage points.
By month
- Jan: 72.9%
- Feb: 78.3%
- Mar: 66.8%
- Apr: 79.6%
- May: 65.4%
- Jun: 69.5%
- Jul: 68.2%
- Aug: 69.7%
- Sep: 76.3%
- Oct: 82.2%
- Nov: 83.1%
- Dec: 76.2%
May is historically the weakest month and November the strongest, a spread of 17.7 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 66.9% from 302 flights
- August 2023: 73.2% from 286 flights
- September 2023: 66.5% from 213 flights
- October 2023: 79.5% from 242 flights
- November 2023: 83.3% from 264 flights
- December 2023: 72.0% from 268 flights
- January 2024: 59.0% from 263 flights
- February 2024: 77.9% from 258 flights
- March 2024: 58.4% from 288 flights
- April 2024: 79.6% from 261 flights
- May 2024: 55.9% from 300 flights
- June 2024: 60.5% from 271 flights
- July 2024: 62.4% from 274 flights
- August 2024: 69.0% from 293 flights
- September 2024: 79.6% from 255 flights
- October 2024: 87.1% from 259 flights
- November 2024: 87.1% from 305 flights
- December 2024: 73.5% from 329 flights
- January 2025: 70.9% from 322 flights
- February 2025: 74.4% from 274 flights
- March 2025: 71.6% from 340 flights
- April 2025: 80.8% from 315 flights
- May 2025: 65.6% from 348 flights
- June 2025: 68.4% from 304 flights
- July 2025: 68.3% from 311 flights
- August 2025: 67.0% from 300 flights
- September 2025: 80.8% from 276 flights
- October 2025: 80.2% from 304 flights
- November 2025: 79.2% from 332 flights
- December 2025: 82.2% from 340 flights
- January 2026: 84.7% from 342 flights
- February 2026: 82.3% from 310 flights
- March 2026: 69.0% from 341 flights
- April 2026: 78.4% from 310 flights
- May 2026: 74.6% from 294 flights
- June 2026: 79.1% from 277 flights
- July 2026: 74.6% from 287 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.7% against 74.3% in the 12 months before — improving by 3.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 10,858 MIA → IAH 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