Carrier route record
UAAUS→DEN
United Airlines · Austin to Denver
- Flights
- 1,915
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on AUS to DEN lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,915 flights. The strongest carrier on the route with a full sample, Frontier Airlines, flew 549 at 84.8% on time.
Frontier Airlines is the most reliable of the three carriers covered here at 84.8% on time across 549 flights.
Key figures
On time
82.7%
Arrivals under 15 minutes late, of 1,887 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
1.20%
National rate is 1.81%
Whole route
78.4%
Every carrier on AUS to DEN, 5,310 flights
These figures cover 1,915 flights between July 2025 and June 2026. The median arrival is 9 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
United against every carrier on AUS to DEN
United flew 1,915 of the 5,310 flights on AUS to DEN, about 36% of it. Its 82.7% on time is 4 points better than the route as a whole, which runs 78.4%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Frontier at 84.8% to Southwest at 72.7%.
The choice of carrier is not cosmetic here. Frontier Airlines arrives on time 84.8% of the time; Southwest Airlines manages 72.7%. Sample sizes sit next to every figure, because a two-point gap across 2,356 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlines | 549 | 84.8% | 92 min | 0.55% | B+ |
| United Airlines (this page) | 1,915 | 82.7% | 69 min | 1.20% | B |
| SkyWest Airlines | 490 | 81.5% | 70 min | 0.61% | B+ |
| Southwest Airlines | 2,356 | 72.7% | 56 min | 0.59% | C+ |
The spread between Frontier and Southwest is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.
Flight by flight
United flight numbers on AUS to DEN
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am185 flights96.7%
- 8am–11am393 flights87.9%
- 11am–2pm540 flights91.2%
- 2pm–5pm265 flights78.3%
- 5pm–8pm410 flights67.2%
- 8pm–5am122 flights68.3%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 96.7% of the time, against 67.2% for the evening window. That is 30 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 540 flights scheduled in it.
Across the year
United on AUS to DEN through the year
July is the worst month at 67.9% on time, 25 points below April, the best at 93.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 193 flights.
Across the week, Tuesday is the strongest day at 87.6% on time and Sunday the weakest at 80.3%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 46% of the 22,000 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.
- 46%Late-arriving aircraft
- 36%National Airspace System
- 15%Carrier
- 2%Extreme weather
46% 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 22,000 reported delay minutes here, that single category outweighs weather by 23 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 22,457 reported delay minutes.
36% 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 8,150 minutes out of 22,000, against a national NAS share of 21%.
Cancellations sit at 1.20% against a national 1.81%, which is ordinary. Diversions add another 0.26%.
Connections and stage length
What a delay here costs
6.3% 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 a little over an hour, which a normal layover absorbs.
The 775 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 runs 79.9% on time across 1,914 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,915 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.
What to do with this
Booking United on AUS to DEN
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 93.3% on time and July 67.9%, a swing of 25 points. If the dates move at all, move them out of July before you think about anything else. 1,887 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to DEN, every carrier
- United on DEN to AUS, the return leg
- Frontier Airlines on AUS to DEN84.8%
- SkyWest Airlines on AUS to DEN81.5%
- Southwest Airlines on AUS to DEN72.7%
- United Airlines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- Denver International (DEN) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.