Carrier route record
NKLAS→IAH
Spirit Airlines · Las Vegas to Houston
- Flights
- 526
- Period
- July 2025 to June 2026
- Share of route
- 15%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on LAS to IAH lands a B, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 526 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Spirit on LAS to IAH from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.6%
Arrivals under 15 minutes late, of 513 completed flights
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
2.47%
National rate is 1.81%
Whole route
83.9%
Every carrier on LAS to IAH, 3,455 flights
These figures cover 526 flights between July 2025 and June 2026. Beyond the headline rate, 8.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Spirit against every carrier on LAS to IAH
Spirit flew 526 of the 3,455 flights on LAS to IAH, about 15% of it. Its 77.6% on time is 6 points worse than the route as a whole, which runs 83.9%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 85.6% to Spirit at 77.6%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,601 | 85.6% | 73 min | 0.58% | A+ |
| Frontier Airlinesthin sample | 328 | 80.2% | 60 min | 1.22% | B |
| Spirit Airlines (this page) | 526 | 77.6% | 92 min | 2.47% | B |
Departure window
When Spirit runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1 flights—
- 8am–11am113 flights80.2%
- 11am–2pm93 flights75.3%
- 2pm–5pm36 flights77.8%
- 5pm–8pm47 flights68.1%
- 8pm–5am236 flights79.1%
Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 80.2% of the time, against 68.1% for the evening window. That is 12 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 236 flights scheduled in it.
Across the year
Spirit on LAS to IAH through the year
October is the best month on the calendar at 91.9% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. August was the busiest month here, with 64 flights.
Across the week, Wednesday is the strongest day at 88.4% on time and Monday the weakest at 73.3%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Spirit runs late on this route
One category carries most of the weight here. Carrier accounts for 52% of the 11,000 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.
- 52%Carrier
- 26%National Airspace System
- 20%Late-arriving aircraft
- 2%Extreme weather
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,501 of the 11,000 delay minutes reported here. The split is drawn from 10,613 reported delay minutes.
Cancellations sit at 2.47% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.2% of arrivals land an hour or more late, close to the national 8.1%. 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 an hour and a half, which a normal layover absorbs.
The 1,222 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 81.9% on time across 527 flights, 4 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
One caution: this is a thin sample. 526 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Spirit on LAS to IAH
Put together: treat all of this as provisional. 526 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 77.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 513 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to IAH, every carrier
- Spirit on IAH to LAS, the return leg
- United Airlines on LAS to IAH85.6%
- Frontier Airlines on LAS to IAH80.2%
- Spirit Airlines network-wide record
- Harry Reid International (LAS) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.