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DelayAtlas

Carrier route record

F9PHXIAH

Frontier Airlines · Phoenix to Houston

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

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

Frontier on PHX to IAH lands a B, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 277 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,780 at 84.6% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on PHX 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

78.5%

Arrivals under 15 minutes late, of 274 completed flights

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

1.08%

National rate is 1.81%

Whole route

81.3%

Every carrier on PHX to IAH, 2,927 flights

These figures cover 277 flights between July 2025 and June 2026. The median arrival is 7 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

Frontier against every carrier on PHX to IAH

Frontier flew 277 of the 2,927 flights on PHX to IAH, about 9% of it. Its 78.5% on time is 3 points worse than the route as a whole, which runs 81.3%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from United at 84.6% to SkyWest 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. United Airlines arrives on time 84.6% of the time; American Airlines manages 75.3%. Sample sizes sit next to every figure, because a two-point gap across 622 flights means less than a ten-point one.

On-time performance by carrier on PHX to IAH
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,78084.6%84 min0.56%B+
Envoy Airthin sample6881.8%29 min0.00%B+
Frontier Airlines (this page)thin sample27778.5%62 min1.08%B
American Airlines62275.3%68 min1.45%B
SkyWest Airlinesthin sample18072.6%81 min2.78%C

United leads American by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 10 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am86 flights83.3%
  • 8am–11am87 flights79.3%
  • 11am–2pm7 flights
  • 2pm–5pm21 flights
  • 5pm–8pm75 flights73.0%
  • 8pm–5am1 flights

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 83.3% of the time, against 73.0% for the evening 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 8am–11am window is the busiest, with 87 flights scheduled in it.

Across the year

Frontier on PHX to IAH through the year

  • Jul–Sep 202554 flights86.8%
  • Oct–Dec 202572 flights72.2%
  • Jan–Mar 202673 flights75.0%
  • Apr–Jun 202678 flights81.8%

Scale runs 65% to 90%. 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 78.5% on time across 277 flights.

Frontier on PHX to IAH did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.8% on time and its weakest Oct–Dec 2025 at 72.2%, a swing of 15 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, Thursday is the strongest day at 85.4% on time and Friday the weakest at 62.5%. 23 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.4MonTueWed85.4Thu62.5Fri83.7Sat84.9Sun
Monday: 77.4 percent on time. Tuesday: not enough flights. Wednesday: not enough flights. Thursday: 85.4 percent on time. Friday: 62.5 percent on time. Saturday: 83.7 percent on time. Sunday: 84.9 percent on time

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. National Airspace System accounts for 42% of the 3,626 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.

  • National Airspace System
    42%
  • Late-arriving aircraft
    30%
  • Carrier
    28%

42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,540 minutes out of 3,626, against a national NAS share of 21%. The split is drawn from 3,626 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 83.3% on time here.

Cancellations sit at 1.08% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

7.3% 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 1,009 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 68.5% on time across 277 flights, 10 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 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 PHX to IAH

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 78.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 274 completed flights over 12 months sit behind that.

Related

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.