Carrier route record
UADEN→BIL
United Airlines · Denver to Billings
- Flights
- 730
- Period
- July 2025 to June 2026
- Share of route
- 41%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to BIL lands a B+, about a point worse than the national rate of 77.6%. About one flight in four 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 730 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to BIL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.6%
Arrivals under 15 minutes late, of 728 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
Whole route
79.6%
Every carrier on DEN to BIL, 1,782 flights
These figures cover 730 flights between July 2025 and June 2026. The median arrival is 4 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 DEN to BIL
United flew 730 of the 1,782 flights on DEN to BIL, about 41% of it. Its 76.6% on time is 3 points worse than the route as a whole, which runs 79.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 81.7% to United at 76.6%.
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 Airlines | 1,052 | 81.7% | 52 min | 1.24% | B |
| United Airlines (this page) | 730 | 76.6% | 61 min | 0.00% | B+ |
Flight by flight
United flight numbers on DEN to BIL
Departure window
When United 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 730 flights.
- 5am–8am—
- 8am–11am1 flights—
- 11am–2pm365 flights77.2%
- 2pm–5pm—
- 5pm–8pm364 flights76.0%
- 8pm–5am—
Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.
The 11am–2pm window is the strongest at 77.2% on time. The full set of windows spans about a point.
Across the year
United on DEN to BIL through the year
July is the worst month at 50.8% on time, 41 points below April, the best at 91.7%. 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. January was the busiest month here, with 62 flights.
Across the week, Wednesday is the strongest day at 79.8% on time and Sunday the weakest at 73.1%. 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 59% of the 10,000 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.
- 59%Late-arriving aircraft
- 30%Carrier
- 9%National Airspace System
- 2%Extreme weather
59% 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 10,000 reported delay minutes here, that single category outweighs weather by 29 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 10,421 reported delay minutes.
Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
7.7% 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.
At 455 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 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 82.7% on time across 730 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 730 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 United on DEN to BIL
Put together: treat all of this as provisional. 730 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 76.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 728 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.