Flight number record
UA 1188
United Airlines · Redmond to Denver
- Route
- RDM → DEN
- Departs
- 05:00
- Flights
- 364
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1188, check with United Airlines.
UA 1188 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 364 flights, with a median arrival 11 minutes early.
Set against the rest of the country, UA 1188's record is 10 points better than the US average of 77.6%. That gap is worth roughly 98 fewer late arrivals for every thousand flights.
Key figures
On time
87.4%
Arrivals under 15 minutes late, of 358 completed flights
Avg delay
94 min
Across delayed arrivals only, not all flights
Cancelled
1.37%
National rate is 1.81%
1 hour+ late
4.5%
National rate is 8.1%
These figures cover 364 flights between July 2025 and June 2026. The median arrival is 11 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 1188 flies
UA 1188 is scheduled to leave Redmond (RDM) at 05:00 local time and reach Denver (DEN) at 08:28. That slot held for 306 of the 364 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 05:00306 flights84.1%
- Departs 05:0537 flights10.2%
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 05:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 1188 runs level with that at 87.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
UA 1188 next to RDM to DEN
Every carrier on RDM to DEN combined arrived on time 85.2% of the time across 728 flights, so UA 1188 is 2 points ahead of it. Across its whole network United Airlines managed 79.0%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1188thin sample | 364 | 87.4% | 94 min | 1.37% | A |
| All United Airlines on RDM–DEN | 728 | 85.2% | 72 min | 0.96% | A+ |
| All carriers on RDM–DEN | 728 | 85.2% | 72 min | 0.96% | A+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1188 quarter by quarter
UA 1188 did not run the same all year. Its best quarter was Apr–Jun 2026 at 92.2% on time and its weakest Oct–Dec 2025 at 81.3%, a swing of 11 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 flights84.6%
- Oct–Dec 202592 flights81.3%
- Jan–Mar 202689 flights91.9%
- Apr–Jun 202691 flights92.2%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1188 did best on Thursday at 96.2% on time and worst on Tuesday at 80.8%. 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 1188 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 4,218 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.
- 48%Late-arriving aircraft
- 41%Carrier
- 10%National Airspace System
- 0%Extreme weather
48% 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 4,218 reported delay minutes here, that single category outweighs weather by 48 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 4,218 delay minutes reported on UA 1188.
Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.27%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.5% 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 898 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 two other city pairs in the data, including DEN to RAP (117) and DEN to TUS (41), but none flew often enough under UA 1188 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to RDM 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 1188
For a booking, UA 1188 has one of the better records a US domestic flight can show: 87.4% on time and 1.37% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- RDM to DEN, every carrier and departure
- DEN to RDM, the return direction
- United Airlines 2035 on the same route80.8%
- 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.