Flight number record
UA 1812
United Airlines · Denver to San Francisco
- Route
- DEN → SFO
- Departs
- 13:25
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1812, check with United Airlines.
UA 1812 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 365 flights, with a median arrival 5 minutes early.
Key figures
On time
73.4%
Arrivals under 15 minutes late, of 365 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
10.1%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. Beyond the headline rate, 10.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 1812 flies
UA 1812 flies DEN to SFO without a single fixed slot. Its most common scheduled departure was 13:25, used on 160 of 365 flights, with 13:30 (75 flights) and 13:40 (53 flights) next.
- Departs 13:25160 flights43.8%
- Departs 13:3075 flights20.5%
- Departs 13:4053 flights14.5%
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 13:25 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and UA 1812 runs 5 points worse at 73.4%. 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 1812 next to DEN to SFO
Every carrier on DEN to SFO combined arrived on time 63.2% of the time across 5,488 flights, so UA 1812 is 10 points ahead of it. United flew 3,429 flights on the same city pair under all its flight numbers, including this one, and those ran 69.0% 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 1812 | 365 | 73.4% | 66 min | 0.00% | C+ |
| All United Airlines on DEN–SFO | 3,429 | 69.0% | 63 min | 0.23% | C+ |
| All carriers on DEN–SFO | 5,488 | 63.2% | 62 min | 0.40% | D+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1812 quarter by quarter
UA 1812 did not run the same all year. Its best quarter was Oct–Dec 2025 at 80.4% on time and its weakest Jul–Sep 2026 at 64.5%, a swing of 16 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 flights80.4%
- Jan–Mar 202690 flights77.8%
- Apr–Jun 202691 flights65.9%
- Jul–Sep 202662 flights64.5%
Scale runs 55% to 85%.
By weekday, UA 1812 ranged from 67.3% on Friday to 78.8% on Tuesday. 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 1812 runs when it is late
UA 1812 often beats the schedule: 97 of 365 completed flights, 27%, arrived 15 minutes or more early. The 97 late arrivals split 33 under half an hour, 27 between 30 and 60 minutes, and 37 an hour or more.
- 15+ min early97 flights26.6%
- Within 15 min171 flights46.8%
- 15–29 min late33 flights9.0%
- 30–59 min late27 flights7.4%
- 1–2 hours late24 flights6.6%
- 2+ hours late13 flights3.6%
Scale runs 0% to 100%.
Share of 365 completed flights by arrival against schedule.
13 of 83 late departures made up the time and arrived on time, 16% of them. In the other direction, 27 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 SFO.
The worst days
Worst days for UA 1812
The latest arrival of the period was on 2 August 2026, 8 hours 48 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as national airspace system delay.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 August 2026 | 8 hours 48 minutes | Late-arriving aircraft |
| 5 November 2025 | 4 hours 29 minutes | National Airspace System |
| 28 May 2026 | 4 hours | National Airspace System |
| 2 January 2026 | 3 hours 33 minutes | National Airspace System |
| 20 April 2026 | 3 hours 13 minutes | National Airspace System |
Delay causes
Why UA 1812 runs late
National Airspace System accounts for 60% of the 6,435 delay minutes carriers reported here, and the remaining four split what is left.
- 60%National Airspace System
- 24%Late-arriving aircraft
- 15%Carrier
- 1%Extreme weather
60% 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 3,839 minutes out of 6,435, against a national NAS share of 21%. The split is drawn from 6,435 delay minutes reported on UA 1812.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
10.1% 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 967 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 SFO to PDX (71), SFO to BUR (31) and SFO to SAN (24), but none flew often enough under UA 1812 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to SFO 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 1812
For a booking, read UA 1812 as 73.4% on time with 0.00% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- DEN to SFO, every carrier and departure
- SFO to DEN, the return direction
- United Airlines 2633 on the same route68.7%
- United Airlines 2391 on the same route71.7%
- United Airlines 2367 on the same route95.3%
- United Airlines 1007 on the same route66.2%
- United Airlines 1561 on the same route66.8%
- United Airlines 2123 on the same route56.6%
- Denver International (DEN) delay statistics
- San Francisco International (SFO) 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
- How often a connection fails at the major US hubs
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.