Route reliability record
AUS→IAH
Austin to Houston
- Flights
- 2,670
- Period
- September 2025 to August 2026
- Distance
- 140 mi
- Carriers
- 2
This route lands a B, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 2,670 AUS to IAH flights, with a median arrival 2 minutes early.
Best time to fly AUS to IAH: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 79.8% of the time and Saturday flights 80.2%, against 77.2% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 2,642 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.01%
National rate is 1.89%
Best carrier
United
77.0% on time across 2,643 flights
These figures cover 2,670 flights between September 2025 and August 2026. The median arrival is 2 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Which airline is most reliable on AUS to IAH
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 27 | 92.6% | 72 min | 0.00% | A+ |
| United Airlines | 2,643 | 77.0% | 58 min | 1.02% | B |
Flight by flight
Flights on AUS to IAH
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Best ways to make this trip
The most reliable ways to fly Austin to Houston
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. AUS → IAHAustin to Houston | United Airlines | 76.2% | 77.0% | 1.02% | 5am–8am, Sat (route) | UA 1966 05:30 |
| 2. AUS → HOUAustin to Houston | Southwest Airlines | 67.0% | 67.3% | 0.39% | 5am–8am, Sat | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
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 2,670 flights.
- 5am–8am717 flights79.8%
- 8am–11am355 flights77.8%
- 11am–2pm342 flights72.9%
- 2pm–5pm599 flights76.9%
- 5pm–8pm657 flights76.5%
- 8pm–5am—
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 72.9% on time against 79.8% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 717 flights scheduled in it.
Explore
Filter AUS to IAH by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On AUS to IAH, the best departure window is 5am–8am at 79.8% on time and the worst is 11am–2pm at 72.9%, a real gap of 6.9 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am79.8%
- 8–11am77.8%
- 11am–2pm72.9%
- 2–5pm76.9%
- 5–8pm76.5%
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 31 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
Delays peak in October, when the on-time rate falls to 62.0%. February is the strongest month at 93.4%. Moving a flexible trip across that boundary buys 31 points. January was the busiest month here, with 239 flights.
Across the week, Saturday is the strongest day at 80.2% on time and Sunday the weakest at 72.1%, a spread of 8 points.
Delay causes
Why this route gets delayed
National Airspace System accounts for 45% of the 35,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%National Airspace System
- 30%Late-arriving aircraft
- 20%Carrier
- 6%Extreme weather
45% 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 15,000 minutes out of 35,000, against a national NAS share of 21%. The split is drawn from 34,731 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 79.8% on time here.
Cancellations sit at 1.01% against a national 1.89%, which is ordinary. Diversions add another 0.04%.
Connections and stage length
What a delay here actually costs
5.4% of arrivals land an hour or more late, close to the national 8.3%, so 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.
At 140 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 80.2% on time across 2,671 flights, 3 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 3 points of difference.
The sample behind these figures is 2,670 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in IAH after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 93.4% on time and October 62.0%, a swing of 31 points. If the dates move at all, move them out of October before you think about anything else. 2,642 completed flights over 12 months sit behind that.
Common questions
AUS to IAH questions
How often is AUS to IAH delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.8% of the 2,670 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is AUS to IAH compared with the rest of the country?
77.2% of flights arrive on time here against a national 77.3%, a difference of half a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on AUS to IAH?
The 5am–8am departure window is the strongest at 79.8% on time. The 11am–2pm window is the weakest at 72.9%, 7 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are October delays on AUS to IAH?
October is the weakest month at 62.0% on time, compared with 93.4% in February. Across the year that is 31 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- IAH to AUS — the return legseparate record
- Austin-Bergstrom International (AUS) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- AUS to DEN, a related route78.9%
- ORD to IAH, a related route76.0%
- AUS to DFW, a related route74.9%
- SkyWest Airlines on-time record92.6%
- United Airlines on-time record77.0%
- Worst months to fly in the US, ranked by the data
- The best day of the week to fly, and why it is the second lever
Direction matters. AUS to IAH and IAH to AUS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed AUS to IAH’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.