Flight number record
UA 2621
United Airlines · Houston to Austin
- Route
- IAH → AUS
- Departs
- 20:18
- Flights
- 326
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2621, check with United Airlines.
UA 2621 sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 326 flights, with a median arrival 4 minutes early.
Key figures
On time
73.8%
Arrivals under 15 minutes late, of 324 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.31%
National rate is 1.89%
1 hour+ late
11.1%
National rate is 8.3%
These figures cover 326 flights between September 2025 and August 2026. Beyond the headline rate, 11.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 2621 flies
UA 2621 flies IAH to AUS without a single fixed slot. Its most common scheduled departure was 20:18, used on 82 of 326 flights, with 20:25 (63 flights) and 20:20 (45 flights) next.
- Departs 20:1882 flights25.2%
- Departs 20:2563 flights19.3%
- Departs 20:2045 flights13.8%
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 20:18 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and UA 2621 runs 4 points better at 73.8%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 2621 next to IAH to AUS
Every carrier on IAH to AUS combined arrived on time 80.2% of the time across 2,671 flights, so UA 2621 is 6 points behind it. United flew 2,645 flights on the same city pair under all its flight numbers, including this one, and those ran 80.1% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2621thin sample | 326 | 73.8% | 66 min | 0.31% | C+ |
| All United Airlines on IAH–AUS | 2,645 | 80.1% | 62 min | 0.72% | B+ |
| All carriers on IAH–AUS | 2,671 | 80.2% | 62 min | 0.71% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 2621 quarter by quarter
UA 2621 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.0% on time and its weakest Oct–Dec 2025 at 68.9%, a swing of 21 points on roughly 65 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 flights90.0%
- Oct–Dec 202590 flights68.9%
- Jan–Mar 202653 flights80.8%
- Apr–Jun 202691 flights70.0%
- Jul–Sep 202662 flights72.6%
Scale runs 60% to 95%.
By weekday, UA 2621 did best on Tuesday at 80.0% on time and worst on Sunday at 63.8%. Each day rests on about 47 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2621 runs when it is late
The 85 late arrivals split 25 under half an hour, 24 between 30 and 60 minutes, and 36 an hour or more.
- 15+ min early69 flights21.3%
- Within 15 min170 flights52.5%
- 15–29 min late25 flights7.7%
- 30–59 min late24 flights7.4%
- 1–2 hours late25 flights7.7%
- 2+ hours late11 flights3.4%
Scale runs 0% to 100%.
Share of 324 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 90 departures that left 15 minutes late or more, only 10 made it up before arrival. Only 5 left on time and still arrived late.
The worst days
Worst days for UA 2621
The latest arrival of the period was on 9 November 2025, 4 hours behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 9 November 2025 | 4 hours | Carrier |
| 11 March 2026 | 3 hours 29 minutes | Late-arriving aircraft |
| 2 June 2026 | 2 hours 58 minutes | Late-arriving aircraft |
| 8 November 2025 | 2 hours 19 minutes | Late-arriving aircraft |
| 29 December 2025 | 2 hours 19 minutes | Carrier |
Delay causes
Why UA 2621 runs late
Late-arriving aircraft accounts for 62% of the 5,571 delay minutes carriers reported here, and the remaining four split what is left.
- 62%Late-arriving aircraft
- 24%Carrier
- 12%National Airspace System
- 2%Extreme weather
62% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,571 reported delay minutes here, that single category outweighs weather by 28 to one. The split is drawn from 5,571 delay minutes reported on UA 2621.
Cancellations are rare at 0.31%, 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
11.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The same number turns up on six other city pairs in the data, including ORD to IAH (55), SFO to IAH (37) and SJC to ORD (31), but none flew often enough under UA 2621 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to AUS only.
One caution: this is a thin sample. 326 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 2621
For a booking, UA 2621 is one of the weaker ways to fly IAH to AUS: 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
- IAH to AUS, every carrier and departure
- AUS to IAH, the return direction
- United Airlines 1711 on the same route68.5%
- United Airlines 1859 on the same route82.7%
- United Airlines 1179 on the same route80.5%
- George Bush Intercontinental (IAH) delay statistics
- Austin-Bergstrom International (AUS) 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.