Flight number record
UA 320
United Airlines · Denver to Houston
- Route
- DEN → IAH
- 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 320, check with United Airlines.
UA 320 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 19 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 364 flights, with a median arrival 16 minutes early.
Set against the rest of the country, UA 320's record is 19 points better than the US average of 77.6%. That gap is worth roughly 188 fewer late arrivals for every thousand flights.
Key figures
On time
96.4%
Arrivals under 15 minutes late, of 362 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.81%
1 hour+ late
1.1%
National rate is 8.1%
These figures cover 364 flights between July 2025 and June 2026. The median arrival is 16 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 320 flies
UA 320 flies DEN to IAH without a single fixed slot. Its most common scheduled departure was 05:00, used on 206 of 364 flights, with 05:02 (101 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 05:00206 flights56.6%
- Departs 05:02101 flights27.7%
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 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 320 runs 7 points better at 96.4%. 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 320 next to DEN to IAH
Every carrier on DEN to IAH combined arrived on time 78.2% of the time across 4,673 flights, so UA 320 is 18 points ahead of it. United flew 3,875 flights on the same city pair under all its flight numbers, including this one, and those ran 78.0% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 17 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 320thin sample | 364 | 96.4% | 59 min | 0.55% | A+ |
| All United Airlines on DEN–IAH | 3,875 | 78.0% | 62 min | 0.23% | B+ |
| All carriers on DEN–IAH | 4,673 | 78.2% | 62 min | 0.21% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 320 quarter by quarter
Quarter by quarter UA 320 held fairly steady: 98.9% in Jul–Sep 2025, 96.7% in Oct–Dec 2025, 93.2% in Jan–Mar 2026 and 96.7% in Apr–Jun 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 flights98.9%
- Oct–Dec 202592 flights96.7%
- Jan–Mar 202689 flights93.2%
- Apr–Jun 202691 flights96.7%
Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 320 ranged from 92.3% on Monday to 100.0% on Tuesday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Delay causes
Why UA 320 runs late
One category carries most of the weight here. National Airspace System accounts for 57% of the 761 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.
- 57%National Airspace System
- 43%Carrier
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 325 of the 761 delay minutes reported here. The split is drawn from 761 delay minutes reported on UA 320.
Cancellations are rare at 0.55%, 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
Badly late arrivals are rare here: only 1.1% 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 861 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 eight other city pairs in the data, including IAH to DFW (50), IAH to CMH (27) and IAH to BWI (19), but none flew often enough under UA 320 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to IAH 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 320
For a booking, UA 320 has one of the better records a US domestic flight can show: 96.4% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- DEN to IAH, every carrier and departure
- IAH to DEN, the return direction
- United Airlines 1720 on the same route89.6%
- United Airlines 475 on the same route73.6%
- United Airlines 2419 on the same route78.6%
- Frontier Airlines 2996 on the same route72.9%
- United Airlines 1829 on the same route69.9%
- United Airlines 489 on the same route75.2%
- Denver International (DEN) delay statistics
- George Bush Intercontinental (IAH) 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.