Carrier route record
NKIAH→LAX
Spirit Airlines · Houston to Los Angeles
- Flights
- 458
- Period
- July 2025 to June 2026
- Share of route
- 9%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on IAH to LAX lands a B, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 458 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 645 at 88.5% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 88.5% on time across 645 flights.
Key figures
On time
83.6%
Arrivals under 15 minutes late, of 451 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.31%
National rate is 1.81%
Whole route
83.6%
Every carrier on IAH to LAX, 5,260 flights
These figures cover 458 flights between July 2025 and June 2026. The median arrival is 16 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Spirit against every carrier on IAH to LAX
Spirit flew 458 of the 5,260 flights on IAH to LAX, about 9% of it. Its 83.6% on time is about level with the route as a whole at 83.6%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from American at 100.0% to Frontier at 72.6%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 88.5% of the time; SkyWest Airlines manages 78.3%. Sample sizes sit next to every figure, because a two-point gap across 408 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines | 645 | 88.5% | 86 min | 1.09% | A |
| United Airlines | 3,416 | 84.4% | 59 min | 0.32% | B+ |
| Spirit Airlines (this page) | 458 | 83.6% | 70 min | 1.31% | B |
| SkyWest Airlines | 408 | 78.3% | 75 min | 0.49% | B+ |
| Frontier Airlinesthin sample | 332 | 72.6% | 60 min | 1.20% | C |
Delta leads SkyWest by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am127 flights91.3%
- 8am–11am15 flights—
- 11am–2pm—
- 2pm–5pm115 flights78.9%
- 5pm–8pm18 flights—
- 8pm–5am183 flights80.9%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.3% of the time, against 78.9% for the afternoon 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 183 flights scheduled in it.
Across the year
Spirit on IAH to LAX through the year
- Jul–Sep 2025185 flights91.3%
- Oct–Dec 2025154 flights81.7%
- Jan–Mar 202689 flights75.0%
- Apr–Jun 202630 flights—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 83.6% on time across 458 flights.
Spirit on IAH to LAX did not run the same all year. Its best quarter was Jul–Sep 2025 at 91.3% on time and its weakest Jan–Mar 2026 at 75.0%, a swing of 16 points on roughly 153 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Tuesday is the strongest day at 93.9% on time and Thursday the weakest at 73.0%. 21 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 43% of the 5,167 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.
- 43%Carrier
- 31%Late-arriving aircraft
- 20%National Airspace System
- 5%Extreme weather
The largest share of delay minutes, 43%, 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 2,241 of the 5,167 delay minutes reported here. The split is drawn from 5,167 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 91.3% on time here.
Cancellations sit at 1.31% against a national 1.81%, which is ordinary. Diversions add another 0.22%.
Connections and stage length
What a delay here costs
5.1% 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 a little over an hour, which a normal layover absorbs.
The 1,379 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 77.5% on time across 455 flights, 6 points below 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 6 points of difference.
One caution: this is a thin sample. 458 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 IAH to LAX
Put together: treat all of this as provisional. 458 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 83.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 451 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to LAX, every carrier
- Spirit on LAX to IAH, the return leg
- Delta Air Lines on IAH to LAX88.5%
- United Airlines on IAH to LAX84.4%
- SkyWest Airlines on IAH to LAX78.3%
- Frontier Airlines on IAH to LAX72.6%
- Spirit Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Los Angeles International (LAX) delay statistics
- Same route, different airline: where the carrier you pick matters most
- The best time of day to fly, according to 7.04 million flight records
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.