Carrier route record
UADEN→BIL
United Airlines · Denver to Billings
- Flights
- 725
- Period
- September 2025 to August 2026
- Share of route
- 41%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to BIL lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 725 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.3%, 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
79.2%
Arrivals under 15 minutes late, of 722 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.14%
National rate is 1.89%
Whole route
80.3%
Every carrier on DEN to BIL, 1,774 flights
These figures cover 725 flights between September 2025 and August 2026. The median arrival is 5 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.
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Carrier by carrier
United against every carrier on DEN to BIL
United flew 725 of the 1,774 flights on DEN to BIL, about 41% of it. Its 79.2% on time is about level with the route as a whole at 80.3%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 81.1% to United at 79.2%.
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 | 1,049 | 81.1% | 71 min | 1.14% | B |
| United Airlines (this page) | 725 | 79.2% | 68 min | 0.14% | B+ |
Flight by flight
United flight numbers on DEN to BIL
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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 725 flights.
- 5am–8am—
- 8am–11am1 flights—
- 11am–2pm361 flights80.8%
- 2pm–5pm—
- 5pm–8pm363 flights77.6%
- 8pm–5am—
Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.
The 11am–2pm window is the strongest at 80.8% on time. The full set of windows spans 3 points.
Across the year
United on DEN to BIL through the year
June is the worst month at 61.7% on time, 30 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 85.6% on time and Saturday the weakest at 73.3%, a spread of 12 points.
Arrival by arrival
How late United on DEN to BIL runs when it is late
The 150 late arrivals split 56 under half an hour, 43 between 30 and 60 minutes, and 51 an hour or more.
- 15+ min early121 flights16.8%
- Within 15 min451 flights62.5%
- 15–29 min late56 flights7.8%
- 30–59 min late43 flights6.0%
- 1–2 hours late34 flights4.7%
- 2+ hours late17 flights2.4%
Scale runs 0% to 100%.
Share of 722 completed flights by arrival against schedule.
26 of 156 late departures made up the time and arrived on time, 17% of them. 20 flights left on time and still arrived late.
The worst days
Worst days for United on DEN to BIL
The latest arrival of the period was on 14 August 2026, 11 hours 43 minutes behind schedule; most of its delay minutes were filed as extreme weather. Three of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 August 2026 | 11 hours 43 minutes | Extreme weather |
| 8 August 2026 | 10 hours 54 minutes | Carrier |
| 27 October 2025 | 10 hours 52 minutes | Carrier |
| 6 March 2026 | 6 hours 6 minutes | Carrier |
| 3 August 2026 | 3 hours 41 minutes | Carrier |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 48% of the 10,000 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Late-arriving aircraft
- 35%Carrier
- 9%National Airspace System
- 7%Extreme weather
48% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 10,000 reported delay minutes here, that single category outweighs weather by 7 to one. The split is drawn from 10,156 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,586 of the 10,000 delay minutes reported here.
Cancellations are rare at 0.14%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
7.1% 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 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 84.1% on time across 725 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 725 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. 725 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 79.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 722 completed flights over 12 months sit behind that.
Related
Where to go next
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.