Carrier route record

F9IAH→LAX

Frontier Airlines · Houston to Los Angeles

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

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

Frontier on IAH to LAX sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 332 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 four carriers covered here at 88.5% on time across 645 flights.

On time

72.6%

Arrivals under 15 minutes late, of 328 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.20%

National rate is 1.81%

Whole route

83.6%

Every carrier on IAH to LAX, 5,260 flights

These figures cover 332 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

Frontier against every carrier on IAH to LAX

Frontier flew 332 of the 5,260 flights on IAH to LAX, about 6% of it. Its 72.6% on time is 11 points worse than the route as a whole, which runs 83.6%. Ranked by on-time rate it is last of six carriers on the route, where the range runs from American at 100.0% to Frontier at 72.6%. One 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.

On-time performance by carrier on IAH to LAX
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	458	83.6%	70 min	1.31%	B
SkyWest Airlines	408	78.3%	75 min	0.49%	B+
Frontier Airlines (this page)thin 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.

Flight by flight

Frontier flight numbers on IAH to LAX

F9 175511:5672.7% · 330 flights

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 332 flights.

5am–8am22 flights—
8am–11am48 flights68.8%
11am–2pm127 flights72.6%
2pm–5pm35 flights71.4%
5pm–8pm77 flights72.4%
8pm–5am23 flights—

Scale runs 60% to 80%. Rows with fewer than 30 flights show a dash.

The time of day barely matters here. The 11am–2pm window tops the set at 72.6% and 8am–11am sits at 68.8%, 4 points apart across 332 flights. Pick the departure that suits the trip: whatever is going wrong here is not accumulating over the course of the day. The 11am–2pm window is the busiest, with 127 flights scheduled in it.

Across the year

Frontier on IAH to LAX through the year

Jul–Sep 202579 flights78.9%
Oct–Dec 202583 flights61.4%
Jan–Mar 202679 flights73.1%
Apr–Jun 202691 flights76.9%

Scale runs 55% to 85%. 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 72.6% on time across 332 flights.

Frontier on IAH to LAX did not run the same all year. Its best quarter was Jul–Sep 2025 at 78.9% on time and its weakest Oct–Dec 2025 at 61.4%, a swing of 18 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 91.2% on time and Friday the weakest at 62.7%. 29 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 51% of the 5,385 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
51%
Carrier
26%
National Airspace System
15%
Extreme weather
8%

51% 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 5,385 reported delay minutes here, that single category outweighs weather by 6 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 5,385 reported delay minutes.

Cancellations sit at 1.20% 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 about 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 68.2% on time across 332 flights, 4 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 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 IAH to LAX

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 72.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 328 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