Carrier route record

F9RDU→IAH

Frontier Airlines · Raleigh to Houston

Flights: 205
Period: July 2025 to June 2026
Share of route: 23%
Carriers: 3

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

Frontier on RDU 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, 5 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 205 flights, with a median arrival 7 minutes early.

The national on-time rate over the same period is 77.6%, so Frontier on RDU to IAH runs 5 points behind the country as a whole. Across a thousand flights that is about 51 extra late arrivals.

On time

72.5%

Arrivals under 15 minutes late, of 200 completed flights

Avg delay

96 min

Across delayed arrivals only, not all flights

Cancelled

2.44%

National rate is 1.81%

Whole route

83.5%

Every carrier on RDU to IAH, 906 flights

These figures cover 205 flights between July 2025 and June 2026. Beyond the headline rate, 10.5% 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 RDU to IAH

Frontier flew 205 of the 906 flights on RDU to IAH, about 23% of it. Its 72.5% on time is 11 points worse than the route as a whole, which runs 83.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 100.0% to Frontier at 72.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on RDU to IAH
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	1	100.0%	—	0.00%	A+
United Airlines	700	86.6%	75 min	0.86%	A+
Frontier Airlines (this page)thin sample	205	72.5%	96 min	2.44%	C

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 20 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am96 flights82.1%
11am–2pm13 flights—
2pm–5pm—
5pm–8pm71 flights61.8%
8pm–5am25 flights—

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 61.8% on time, against 82.1% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 96 flights scheduled in it.

Across the year

Frontier on RDU to IAH through the year

Jul–Sep 202538 flights71.1%
Oct–Dec 202556 flights63.5%
Jan–Mar 202646 flights73.3%
Apr–Jun 202665 flights80.0%

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 72.5% on time across 205 flights.

Frontier on RDU to IAH did not run the same all year. Its best quarter was Apr–Jun 2026 at 80.0% on time and its weakest Oct–Dec 2025 at 63.5%, a swing of 17 points on roughly 51 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 81.2% on time and Monday the weakest at 62.9%. 18 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 75% of the 5,294 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
75%
National Airspace System
16%
Carrier
9%

75% 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 5,294 reported delay minutes here, that single category outweighs weather by 75 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 5,294 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 82.1% on time here.

Cancellations sit at 2.44% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

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. 10.5% 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 1,042 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 76.9% on time across 205 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. 205 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 RDU to IAH

Put together: treat all of this as provisional. 205 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 72.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 200 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