Flight number record
UA 1125
United Airlines · Denver to Boise
- Route
- DEN → BOI
- Departs
- 11:30
- Flights
- 271
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1125, check with United Airlines.
UA 1125 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 271 flights, with a median arrival 5 minutes early.
Set against the rest of the country, UA 1125's record is 8 points better than the US average of 77.6%. That gap is worth roughly 83 fewer late arrivals for every thousand flights.
Key figures
On time
85.9%
Arrivals under 15 minutes late, of 270 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
3.7%
National rate is 8.1%
These figures cover 271 flights between July 2025 and June 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.
Schedule
When UA 1125 flies
UA 1125 flies DEN to BOI without a single fixed slot. Its most common scheduled departure was 11:30, used on 80 of 271 flights, with 11:31 (47 flights) and 11:36 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 11:3080 flights29.5%
- Departs 11:3147 flights17.3%
- Departs 11:3637 flights13.7%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 11:30 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1125 runs 7 points better at 85.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 1125 next to DEN to BOI
Every carrier on DEN to BOI combined arrived on time 76.3% of the time across 3,039 flights, so UA 1125 is 10 points ahead of it. United flew 946 flights on the same city pair under all its flight numbers, including this one, and those ran 79.2% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 7 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1125thin sample | 271 | 85.9% | 59 min | 0.00% | A+ |
| All United Airlines on DEN–BOI | 946 | 79.2% | 57 min | 0.32% | B+ |
| All carriers on DEN–BOI | 3,039 | 76.3% | 55 min | 0.20% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1125 quarter by quarter
Quarter by quarter UA 1125 held fairly steady: 84.8% in Jul–Sep 2025, 83.7% in Oct–Dec 2025 and 89.5% in Jan–Mar 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202592 flights84.8%
- Oct–Dec 202592 flights83.7%
- Jan–Mar 202687 flights89.5%
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1125 did best on Friday at 94.9% on time and worst on Monday at 78.9%. Each day rests on about 39 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 1125 runs late
One category carries most of the weight here. Carrier accounts for 44% of the 2,237 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.
- 44%Carrier
- 38%Late-arriving aircraft
- 18%National Airspace System
38% 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 2,237 reported delay minutes here, that single category outweighs weather by 38 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 2,237 delay minutes reported on UA 1125.
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 routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.7% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 649 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 same number turns up on five other city pairs in the data, including OGG to SFO (41), CMH to LAX (29) and GJT to DEN (21), but none flew often enough under UA 1125 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to BOI only.
One caution: this is a thin sample. 271 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 UA 1125
For a booking, UA 1125 has one of the better records a US domestic flight can show: 85.9% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- DEN to BOI, every carrier and departure
- BOI to DEN, the return direction
- United Airlines 2014 on the same route71.5%
- SkyWest Airlines 5923 on the same route67.3%
- Denver International (DEN) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.