Flight number record
UA 1255
United Airlines · Spokane to Denver
- Route
- GEG → DEN
- Departs
- 13:37
- Flights
- 364
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1255, check with United Airlines.
UA 1255 lands a B+, level with the national rate of 77.6%. Roughly one flight in five 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 364 flights, with a median arrival 6 minutes early.
Key figures
On time
78.1%
Arrivals under 15 minutes late, of 360 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
0.27%
National rate is 1.81%
1 hour+ late
8.3%
National rate is 8.1%
These figures cover 364 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When UA 1255 flies
UA 1255 flies GEG to DEN without a single fixed slot. Its most common scheduled departure was 13:37, used on 73 of 364 flights, with 13:47 (71 flights) and 13:38 (68 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 13:3773 flights20.1%
- Departs 13:4771 flights19.5%
- Departs 13:3868 flights18.7%
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 13:37 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1255 runs level with that at 78.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 1255 next to GEG to DEN
Every carrier on GEG to DEN combined arrived on time 83.8% of the time across 2,063 flights, so UA 1255 is 6 points behind it. United flew 833 flights on the same city pair under all its flight numbers, including this one, and those ran 85.4% on time. Across its whole network United Airlines managed 79.0%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1255thin sample | 364 | 78.1% | 71 min | 0.27% | B+ |
| All United Airlines on GEG–DEN | 833 | 85.4% | 83 min | 0.36% | A+ |
| All carriers on GEG–DEN | 2,063 | 83.8% | 68 min | 0.24% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1255 quarter by quarter
UA 1255 did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.0% on time and its weakest Jul–Sep 2025 at 57.8%, a swing of 33 points on roughly 91 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202592 flights57.8%
- Oct–Dec 202591 flights81.3%
- Jan–Mar 202690 flights82.2%
- Apr–Jun 202691 flights91.0%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1255 did best on Sunday at 88.5% on time and worst on Monday at 74.0%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 1255 runs late
One category carries most of the weight here. National Airspace System accounts for 46% of the 5,642 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%National Airspace System
- 41%Late-arriving aircraft
- 13%Carrier
- 0%Extreme weather
41% 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 5,642 reported delay minutes here, that single category outweighs weather by 41 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 5,642 delay minutes reported on UA 1255.
Cancellations are rare at 0.27%, below the national 1.81% 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 routes
What a delay on this flight costs
8.3% 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 836 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 one other city pair in the data, including DEN to MEM (35), but none flew often enough under UA 1255 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to GEG to DEN only.
One caution: this is a thin sample. 364 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 1255
For a booking, UA 1255 is one of the weaker ways to fly GEG to DEN: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- GEG to DEN, every carrier and departure
- DEN to GEG, the return direction
- 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.