Flight number record
UA 621
United Airlines · Albuquerque to Denver
- Route
- ABQ → DEN
- Departs
- 07:00
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 621, check with United Airlines.
UA 621 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 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 365 flights, with a median arrival 9 minutes early.
Set against the rest of the country, UA 621's record is 14 points better than the US average of 77.3%. That gap is worth roughly 136 fewer late arrivals for every thousand flights.
Key figures
On time
90.9%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.89%
1 hour+ late
2.2%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 9 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 621 flies
UA 621 is scheduled to leave Albuquerque (ABQ) at 07:00 local time and reach Denver (DEN) at 08:23. That slot held for 364 of the 365 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 07:00364 flights99.7%
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 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 621 runs level with that at 90.9%. 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 621 next to ABQ to DEN
Every carrier on ABQ to DEN combined arrived on time 82.3% of the time across 3,216 flights, so UA 621 is 9 points ahead of it. United flew 845 flights on the same city pair under all its flight numbers, including this one, and those ran 83.0% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 621 | 365 | 90.9% | 66 min | 0.82% | A+ |
| All United Airlines on ABQ–DEN | 845 | 83.0% | 78 min | 0.83% | B+ |
| All carriers on ABQ–DEN | 3,216 | 82.3% | 69 min | 0.59% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 621 quarter by quarter
Quarter by quarter UA 621 held fairly steady: 93.3% in Jul–Sep 2025, 90.1% in Oct–Dec 2025, 93.3% in Jan–Mar 2026, 90.0% in Apr–Jun 2026 and 88.3% in Jul–Sep 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights93.3%
- Oct–Dec 202592 flights90.1%
- Jan–Mar 202690 flights93.3%
- Apr–Jun 202691 flights90.0%
- Jul–Sep 202662 flights88.3%
Scale runs 80% to 100%.
By weekday, UA 621 ranged from 86.3% on Saturday to 98.1% on Monday. With about 52 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 621 runs when it is late
UA 621 often beats the schedule: 103 of 361 completed flights, 29%, arrived 15 minutes or more early. Most of the lateness is short. 18 of the 33 late arrivals were under half an hour behind, and 8 reached an hour or more.
- 15+ min early103 flights28.5%
- Within 15 min225 flights62.3%
- 15–29 min late18 flights5.0%
- 30–59 min late7 flights1.9%
- 1–2 hours late2 flights0.6%
- 2+ hours late6 flights1.7%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 23 departures that left 15 minutes late or more, only 2 made it up before arrival. 12 flights left on time and still arrived late.
The worst days
Worst days for UA 621
The latest arrival of the period was on 8 October 2025, 5 hours 46 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 October 2025 | 5 hours 46 minutes | Carrier |
| 15 October 2025 | 4 hours 3 minutes | Carrier |
| 1 January 2026 | 3 hours 44 minutes | Carrier |
| 7 August 2026 | 3 hours 23 minutes | Carrier |
| 7 March 2026 | 3 hours 11 minutes | Carrier |
Delay causes
Why UA 621 runs late
Carrier accounts for 75% of the 2,160 delay minutes carriers reported here, and the remaining four split what is left.
- 75%Carrier
- 24%National Airspace System
- 0%Extreme weather
The largest share of delay minutes, 75%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,625 of the 2,160 delay minutes reported here. The split is drawn from 2,160 delay minutes reported on UA 621.
Cancellations are rare at 0.82%, 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 routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.2% land an hour or more behind schedule, against 8.3% 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 same number turns up on one other city pair in the data, including DEN to GSP (20), but none flew often enough under UA 621 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ABQ to DEN only.
One caution: this is a thin sample. 365 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 621
For a booking, UA 621 has one of the better records a US domestic flight can show: 90.9% on time and 0.82% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- ABQ to DEN, every carrier and departure
- DEN to ABQ, the return direction
- SkyWest Airlines 5834 on the same route92.2%
- United Airlines 1741 on the same route82.4%
- Albuquerque International Sunport (ABQ) delay statistics
- 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
- Worst months to fly in the US, ranked by the data
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.