Carrier route record

F9LAX→IAH

Frontier Airlines · Los Angeles to Houston

Flights: 332
Period: July 2025 to June 2026
Share of route: 6%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on LAX to IAH sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 332 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,415 at 87.1% on time.

United Airlines is the most reliable of the four carriers covered here at 87.1% on time across 3,415 flights.

On time

68.2%

Arrivals under 15 minutes late, of 324 completed flights

Avg delay

71 min

Across delayed arrivals only, not all flights

Cancelled

2.11%

National rate is 1.81%

Whole route

84.6%

Every carrier on LAX to IAH, 5,255 flights

These figures cover 332 flights between July 2025 and June 2026. Beyond the headline rate, 14.8% 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

Frontier against every carrier on LAX to IAH

Frontier flew 332 of the 5,255 flights on LAX to IAH, about 6% of it. Its 68.2% on time is 16 points worse than the route as a whole, which runs 84.6%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 87.1% to Frontier at 68.2%.

The choice of carrier is not cosmetic here. United Airlines arrives on time 87.1% of the time; Spirit Airlines manages 77.5%. Sample sizes sit next to every figure, because a two-point gap across 455 flights means less than a ten-point one.

On-time performance by carrier on LAX to IAH
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	3,415	87.1%	55 min	0.26%	A+
Delta Air Lines	645	86.1%	73 min	1.09%	A
SkyWest Airlines	408	82.0%	68 min	0.49%	B+
Spirit Airlines	455	77.5%	83 min	1.32%	B
Frontier Airlines (this page)thin sample	332	68.2%	71 min	2.11%	C

United leads Spirit by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Flight by flight

Frontier flight numbers on LAX to IAH

F9 175614:2367.6% · 306 flights

Departure window

When Frontier 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–8am—
8am–11am57 flights76.4%
11am–2pm103 flights70.6%
2pm–5pm172 flights64.1%
5pm–8pm—
8pm–5am—

Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 76.4% of the time, against 64.1% 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 2pm–5pm window is the busiest, with 172 flights scheduled in it.

Across the year

Frontier on LAX to IAH through the year

Jul–Sep 202579 flights65.8%
Oct–Dec 202583 flights63.4%
Jan–Mar 202679 flights68.8%
Apr–Jun 202691 flights74.2%

Scale runs 55% to 80%. 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 68.2% on time across 332 flights.

Frontier on LAX to IAH did not run the same all year. Its best quarter was Apr–Jun 2026 at 74.2% on time and its weakest Oct–Dec 2025 at 63.4%, a swing of 11 points on roughly 83 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, Wednesday is the strongest day at 87.9% on time and Monday the weakest at 58.0%. 30 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 7,332 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.

Late-arriving aircraft
50%
Carrier
29%
National Airspace System
19%
Extreme weather
2%

50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 7,332 reported delay minutes here, that single category outweighs weather by 22 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 7,332 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 76.4% on time here.

Cancellations sit at 2.11% against a national 1.81%, which is ordinary. Diversions add another 0.30%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

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 72.6% on time across 332 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. 332 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 Frontier on LAX to IAH

Put together: treat all of this as provisional. 332 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 68.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 324 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures