Route profile
IAH→LAS
Flight reliability, delays and best times to fly from Houston to Las Vegas, 1,222 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 55% of comparable major US routes (4,598 compared)
Calculated from 11,900 flights. How this is calculated
IAH → LAS arrives on time 79.8% of the time; the return trip, LAS → IAH, arrives on time 82.5% of the time, a 2.6-point gap between the two directions of the same city pair.
IAH → LAS spends 27.7 minutes on the ground on a 1,222-mile trip: 19.3 minutes from pushback to wheels-up at IAH and 8.4 minutes from touchdown to gate at LAS.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Why IAH → LAS flights are cancelled
July 2023 – July 2026
IAH → LAS cancelled 122 of 11,900 scheduled flights — about 1 in every 98. The reason filed most often was extreme weather, 51.6% of the cancellations coded on this route — about 1 in every 189 scheduled flights.
Share of cancellations
Of 122 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.
63 cancellations, 51.6% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
51 cancellations, 41.8% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
8 cancellations, 6.6% 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.
122 coded cancellations were recorded on IAH → LAS; the section appears from 50.
When it goes wrong
July 2023 – July 2026
44 min late
against a median of 7 min early
Percentiles over 11,900 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at LAS after arriving from IAH.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 35% | Likely to miss |
| 45 min | 20% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 7.5% | Some risk |
| 120 min | 4.6% | Low 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 1.03% of the time and diverts 0.10% of the time, which a late arrival never shows up in.
Chance of missing is the share of 11,766 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 44 minutes late (90th-percentile gate arrival delay), over 11,900 operations.
Any other layover length: connection checker.
Best time to fly
IAH → LAS flights departing 5–9 AM arrived on time 91.0% of the time, against 72.9% for 6–9 PM departures, a gap of 18.1 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 91.4% on time from 398 flights
- 7 AM: 91.4% on time from 1,260 flights
- 8 AM: 90.4% on time from 172 flights
- 9 AM: 86.2% on time from 1,350 flights
- 10 AM: 74.3% on time from 187 flights
- 11 AM: 83.6% on time from 306 flights
- 12 PM: 82.9% on time from 1,035 flights
- 1 PM: 77.0% on time from 383 flights
- 2 PM: 79.5% on time from 1,363 flights
- 3 PM: 71.1% on time from 203 flights
- 4 PM: 78.8% on time from 775 flights
- 5 PM: 70.2% on time from 415 flights
- 6 PM: 75.8% on time from 1,256 flights
- 7 PM: 65.7% on time from 334 flights
- 8 PM: 72.0% on time from 1,296 flights
- 9 PM: 75.0% on time from 705 flights
- 10 PM: 74.9% on time from 340 flights
- 11 PM: too few flights to score
Why IAH → LAS 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 → LAS. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on IAH → LAS, at 39.1%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 91.0% of the time and 6–9 PM departures 72.9%.
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 LAS: 3.4 times the normal rate at IAH and 2.4 times at LAS. Cancelled in bad weather against normal hours: IAH 4.1% against 1.2%, LAS 2.0% against 0.8%. Flights that did leave LAS in bad weather arrived on time 58.5% of the time, against 78.5% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | IAH | LAS |
|---|---|---|
| Cancelled in bad weather | 4.1% | 2.0% |
| Cancelled in normal hours | 1.2% | 0.8% |
| Arrived on time, bad weather | 63.8% | 58.5% |
| Arrived on time, normal hours | 78.6% | 78.5% |
| Departures in bad weather | 28,922 | 14,522 |
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% |
| Frontier Airlines | 915 | 5.0%above the others | 3.8% |
These are airport figures, not route figures: every scheduled departure from IAH and LAS, 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), LAS, 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 |
|---|---|---|---|---|---|
| United Airlines | 7,546 | 81.3% | 0.80% | -7 min | 7.0% |
| Spirit Airlines | 2,491 | 78.7% | 1.12% | -6 min | 7.8% |
| Southwest Airlines | 941 | 79.6% | 0.96% | -3 min | 6.8% |
| Frontier Airlines | 922 | 71.1% | 2.71% | -5 min | 13.3% |
United Airlines flew 63.4% of the 11,900 flights listed. Frontier Airlines cancelled 2.71% of its flights here against 0.80% for United Airlines.
United Airlines arrived on time 10.2 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 |
|---|---|---|---|
| UA1799 United Airlines | 9:45 AM | 674 | 86.5% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Friday the least, a gap of 9.4 percentage points.
By month
- Jan: 81.0%
- Feb: 87.4%
- Mar: 80.7%
- Apr: 80.2%
- May: 73.0%
- Jun: 71.4%
- Jul: 70.8%
- Aug: 80.7%
- Sep: 80.6%
- Oct: 84.0%
- Nov: 83.5%
- Dec: 86.2%
July is historically the weakest month and February the strongest, a spread of 16.6 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 77.6% from 355 flights
- August 2023: 84.2% from 314 flights
- September 2023: 79.8% from 334 flights
- October 2023: 81.5% from 384 flights
- November 2023: 85.1% from 363 flights
- December 2023: 88.5% from 356 flights
- January 2024: 77.9% from 330 flights
- February 2024: 81.6% from 310 flights
- March 2024: 75.7% from 375 flights
- April 2024: 77.8% from 361 flights
- May 2024: 65.7% from 379 flights
- June 2024: 71.3% from 359 flights
- July 2024: 56.5% from 363 flights
- August 2024: 78.7% from 321 flights
- September 2024: 79.4% from 327 flights
- October 2024: 87.3% from 387 flights
- November 2024: 85.5% from 365 flights
- December 2024: 79.9% from 330 flights
- January 2025: 77.9% from 312 flights
- February 2025: 90.2% from 296 flights
- March 2025: 82.6% from 336 flights
- April 2025: 84.6% from 318 flights
- May 2025: 74.6% from 315 flights
- June 2025: 69.4% from 289 flights
- July 2025: 75.4% from 291 flights
- August 2025: 79.2% from 286 flights
- September 2025: 83.1% from 255 flights
- October 2025: 83.2% from 292 flights
- November 2025: 79.4% from 311 flights
- December 2025: 90.2% from 307 flights
- January 2026: 87.9% from 282 flights
- February 2026: 90.9% from 291 flights
- March 2026: 84.8% from 323 flights
- April 2026: 78.4% from 295 flights
- May 2026: 81.7% from 263 flights
- June 2026: 73.9% from 261 flights
- July 2026: 75.0% from 264 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 82.5% against 80.7% in the 12 months before — improving by 1.8 percentage points.
Data and methodology
Calculated by FlyerIntel from 11,900 IAH → LAS 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