Flight number record
UA 1188
United Airlines · Redmond to Denver
- Route
- RDM → DEN
- Departs
- 05:00
- Flights
- 364
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 364 flights, with a median arrival 10 minutes early.
Set against the rest of the country, UA 1188's record is 10 points better than the US average of 77.3%. That gap is worth roughly 102 fewer late arrivals for every thousand flights.
Key figures
On time
87.5%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
101 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.89%
1 hour+ late
5.6%
National rate is 8.3%
These figures cover 364 flights between September 2025 and August 2026. The median arrival is 10 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 319 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 05:00319 flights87.6%
Scale runs 0% to 100%.
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 87.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
UA 1188 next to RDM to DEN
Every carrier on RDM to DEN combined arrived on time 85.0% of the time across 727 flights, so UA 1188 is 3 points ahead of it. Across its whole network United Airlines managed 78.8%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1188thin sample | 364 | 87.5% | 101 min | 1.10% | A |
| All United Airlines on RDM–DEN | 727 | 85.0% | 78 min | 0.83% | A+ |
| All carriers on RDM–DEN | 727 | 85.0% | 78 min | 0.83% | A+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | 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 Jul–Sep 2025 at 80.0%, a swing of 12 points on roughly 73 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 202530 flights80.0%
- Oct–Dec 202592 flights81.3%
- Jan–Mar 202689 flights91.9%
- Apr–Jun 202691 flights92.2%
- Jul–Sep 202662 flights87.1%
Scale runs 70% to 100%.
By weekday, UA 1188 did best on Thursday at 94.2% on time and worst on Tuesday at 80.4%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1188 runs when it is late
UA 1188 often beats the schedule: 129 of 359 completed flights, 36%, arrived 15 minutes or more early. The 45 late arrivals split 18 under half an hour, 7 between 30 and 60 minutes, and 20 an hour or more.
- 15+ min early129 flights35.9%
- Within 15 min185 flights51.5%
- 15–29 min late18 flights5.0%
- 30–59 min late7 flights1.9%
- 1–2 hours late10 flights2.8%
- 2+ hours late10 flights2.8%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
7 of 39 late departures made up the time and arrived on time, 18% of them. 13 flights left on time and still arrived late.
The worst days
Worst days for UA 1188
The latest arrival of the period was on 6 February 2026, 10 hours behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in February 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 February 2026 | 10 hours | Late-arriving aircraft |
| 16 February 2026 | 6 hours 38 minutes | Late-arriving aircraft |
| 15 February 2026 | 6 hours 19 minutes | Late-arriving aircraft |
| 20 January 2026 | 5 hours 55 minutes | Late-arriving aircraft |
| 5 November 2025 | 5 hours 54 minutes | Late-arriving aircraft |
Delay causes
Why UA 1188 runs late
Late-arriving aircraft accounts for 45% of the 4,532 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Late-arriving aircraft
- 44%Carrier
- 11%National Airspace System
- 0%Extreme weather
45% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,532 reported delay minutes here, that single category outweighs weather by 45 to one. The split is drawn from 4,532 delay minutes reported on UA 1188.
Cancellations sit at 1.10% against a national 1.89%, which is ordinary. Diversions add another 0.27%.
Connections and routes
What a delay on this flight costs
5.6% 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 close to two hours, which a normal layover absorbs.
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.
The same number turns up on two other city pairs in the data, including DEN to TUS (103) and DEN to RAP (55), 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: 87.5% on time and 1.10% 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
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.