Carrier route record

F9IAH→PHX

Frontier Airlines · Houston to Phoenix

Flights: 277
Period: July 2025 to June 2026
Share of route: 9%
Carriers: 5

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

Frontier on IAH to PHX 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 277 flights. The strongest carrier on the route with a full sample, American Airlines, flew 622 at 81.6% on time.

The national on-time rate over the same period is 77.6%, so Frontier on IAH to PHX runs 9 points behind the country as a whole. Across a thousand flights that is about 91 extra late arrivals.

On time

68.5%

Arrivals under 15 minutes late, of 273 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

1.08%

National rate is 1.81%

Whole route

78.7%

Every carrier on IAH to PHX, 2,930 flights

These figures cover 277 flights between July 2025 and June 2026. Beyond the headline rate, 11.0% 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 PHX

Frontier flew 277 of the 2,930 flights on IAH to PHX, about 9% of it. Its 68.5% on time is 10 points worse than the route as a whole, which runs 78.7%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from Envoy at 83.3% to Frontier at 68.5%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on IAH to PHX
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Airthin sample	67	83.3%	98 min	1.49%	B
American Airlines	622	81.6%	168 min	1.45%	B
United Airlines	1,784	80.0%	64 min	0.34%	B+
SkyWest Airlinesthin sample	180	69.7%	76 min	2.78%	C
Frontier Airlines (this page)thin sample	277	68.5%	74 min	1.08%	C

No carrier stands out. American tops the table at 81.6%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.

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 277 flights.

5am–8am—
8am–11am33 flights75.0%
11am–2pm117 flights67.8%
2pm–5pm25 flights—
5pm–8pm9 flights—
8pm–5am93 flights65.2%

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 75.0% of the time, against 65.2% for the overnight window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 117 flights scheduled in it.

Across the year

Frontier on IAH to PHX through the year

Jul–Sep 202554 flights78.8%
Oct–Dec 202572 flights66.7%
Jan–Mar 202673 flights65.3%
Apr–Jun 202678 flights66.2%

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 68.5% on time across 277 flights.

Frontier on IAH to PHX did not run the same all year. Its best quarter was Jul–Sep 2025 at 78.8% on time and its weakest Jan–Mar 2026 at 65.3%, a swing of 14 points on roughly 69 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, Sunday is the strongest day at 77.4% on time and Friday the weakest at 55.3%. 22 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 56% of the 6,372 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
56%
Carrier
27%
National Airspace System
15%
Extreme weather
2%

56% 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 6,372 reported delay minutes here, that single category outweighs weather by 27 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 6,372 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 75.0% on time here.

Cancellations sit at 1.08% against a national 1.81%, which is ordinary. Diversions add another 0.36%.

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. 11.0% 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 1,009 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 78.5% on time across 277 flights, 10 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 10 points of difference.

One caution: this is a thin sample. 277 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 PHX

Put together: treat all of this as provisional. 277 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 68.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 273 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