Flight number record
UA 1812
United Airlines · Denver to San Francisco
- Route
- DEN → SFO
- Departs
- 13:25
- Flights
- 316
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1812, check with United Airlines.
UA 1812 sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 316 flights, with a median arrival 6 minutes early.
Key figures
On time
75.3%
Arrivals under 15 minutes late, of 316 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
10.4%
National rate is 8.1%
These figures cover 316 flights between July 2025 and June 2026. Beyond the headline rate, 10.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
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 118 of 316 flights, with 13:30 (68 flights) and 13:40 (53 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 13:25118 flights37.3%
- Departs 13:3068 flights21.5%
- Departs 13:4053 flights16.8%
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 13:25 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1812 runs 4 points worse at 75.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 1812 next to DEN to SFO
Every carrier on DEN to SFO combined arrived on time 65.8% of the time across 5,415 flights, so UA 1812 is 10 points ahead of it. United flew 3,373 flights on the same city pair under all its flight numbers, including this one, and those ran 71.2% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1812thin sample | 316 | 75.3% | 67 min | 0.00% | B+ |
| All United Airlines on DEN–SFO | 3,373 | 71.2% | 63 min | 0.42% | C+ |
| All carriers on DEN–SFO | 5,415 | 65.8% | 61 min | 0.48% | C+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | 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 Apr–Jun 2026 at 65.9%, a swing of 15 points on roughly 79 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 202543 flights79.1%
- Oct–Dec 202592 flights80.4%
- Jan–Mar 202690 flights77.8%
- Apr–Jun 202691 flights65.9%
Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1812 ranged from 68.9% on Friday to 80.4% on Tuesday. With about 45 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.
Delay causes
Why UA 1812 runs late
One category carries most of the weight here. National Airspace System accounts for 64% of the 5,234 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.
- 64%National Airspace System
- 23%Late-arriving aircraft
- 13%Carrier
- 1%Extreme weather
64% 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 3,355 minutes out of 5,234, against a national NAS share of 21%. The split is drawn from 5,234 delay minutes reported on UA 1812.
Cancellations are rare at 0.00%, below the national 1.81% 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.4% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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. 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 five other city pairs in the data, including SFO to PDX (53), SFO to ANC (49) and SFO to SAN (37), 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. 316 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 75.3% on time with 0.00% cancelled over 316 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 route75.4%
- United Airlines 2367 on the same route95.3%
- United Airlines 1007 on the same route67.6%
- United Airlines 1561 on the same route71.0%
- United Airlines 2391 on the same route70.8%
- Frontier Airlines 3439 on the same route68.6%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.