Flight number record
UA 1281
United Airlines · Denver to San Diego
- Route
- DEN → SAN
- Departs
- 15:55
- Flights
- 308
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1281, check with United Airlines.
UA 1281 lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 308 flights, with a median arrival 7 minutes early.
Set against the rest of the country, UA 1281's record is 6 points better than the US average of 77.3%. That gap is worth roughly 60 fewer late arrivals for every thousand flights.
Key figures
On time
83.3%
Arrivals under 15 minutes late, of 306 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.32%
National rate is 1.89%
1 hour+ late
6.9%
National rate is 8.3%
These figures cover 308 flights between September 2025 and August 2026. The median arrival is 7 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.
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Schedule
When UA 1281 flies
UA 1281 flies DEN to SAN without a single fixed slot. Its most common scheduled departure was 15:55, used on 134 of 308 flights, with 16:05 (38 flights) and 15:45 (32 flights) next.
- Departs 15:55134 flights43.5%
- Departs 16:0538 flights12.3%
- Departs 15:4532 flights10.4%
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 15:55 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and UA 1281 runs 11 points better at 83.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
UA 1281 next to DEN to SAN
Every carrier on DEN to SAN combined arrived on time 73.8% of the time across 6,152 flights, so UA 1281 is 10 points ahead of it. United flew 2,067 flights on the same city pair under all its flight numbers, including this one, and those ran 77.9% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1281thin sample | 308 | 83.3% | 59 min | 0.32% | B+ |
| All United Airlines on DEN–SAN | 2,067 | 77.9% | 59 min | 0.34% | B+ |
| All carriers on DEN–SAN | 6,152 | 73.8% | 56 min | 0.83% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1281 quarter by quarter
UA 1281 did not run the same all year. Its best quarter was Oct–Dec 2025 at 92.7% on time and its weakest Jul–Sep 2026 at 59.0%, a swing of 34 points on roughly 62 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 202541 flights92.7%
- Jan–Mar 202685 flights90.4%
- Apr–Jun 202691 flights90.1%
- Jul–Sep 202661 flights59.0%
Scale runs 50% to 100%.
By weekday, UA 1281 did best on Saturday at 90.7% on time and worst on Thursday at 76.2%. Each day rests on about 44 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1281 runs when it is late
UA 1281 often beats the schedule: 88 of 306 completed flights, 29%, arrived 15 minutes or more early. The 51 late arrivals split 16 under half an hour, 14 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early88 flights28.8%
- Within 15 min167 flights54.6%
- 15–29 min late16 flights5.2%
- 30–59 min late14 flights4.6%
- 1–2 hours late16 flights5.2%
- 2+ hours late5 flights1.6%
Scale runs 0% to 100%.
Share of 306 completed flights by arrival against schedule.
12 of 47 late departures made up the time and arrived on time, 26% of them. In the other direction, 16 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SAN.
The worst days
Worst days for UA 1281
The latest arrival of the period was on 23 August 2026, 3 hours 11 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across August, February, May, June and September, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 23 August 2026 | 3 hours 11 minutes | National Airspace System |
| 17 February 2026 | 3 hours 10 minutes | Late-arriving aircraft |
| 26 May 2026 | 2 hours 34 minutes | Late-arriving aircraft |
| 5 June 2026 | 2 hours 14 minutes | Carrier |
| 7 September 2025 | 2 hours | Carrier |
Delay causes
Why UA 1281 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 2,985 reported delay minutes.
- 39%National Airspace System
- 32%Late-arriving aircraft
- 25%Carrier
- 4%Extreme weather
39% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,165 minutes out of 2,985, against a national NAS share of 21%. The split is drawn from 2,985 delay minutes reported on UA 1281.
Cancellations are rare at 0.32%, 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
6.9% 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 about an hour, which a normal layover absorbs.
The 853 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 four other city pairs in the data, including EWR to CLE (37), ORD to MSP (21) and MSP to DEN (21), but none flew often enough under UA 1281 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to SAN only.
One caution: this is a thin sample. 308 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 1281
For a booking, read UA 1281 as 83.3% on time with 0.32% cancelled over 308 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- DEN to SAN, every carrier and departure
- SAN to DEN, the return direction
- United Airlines 1940 on the same route78.4%
- United Airlines 540 on the same route63.5%
- United Airlines 1302 on the same route83.6%
- United Airlines 2309 on the same route90.9%
- Frontier Airlines 4989 on the same route73.6%
- Denver International (DEN) delay statistics
- San Diego International (SAN) 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.