Flight number record
UA 1561
United Airlines · Denver to San Francisco
- Route
- DEN → SFO
- Departs
- 11:35
- Flights
- 297
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1561, check with United Airlines.
UA 1561 sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land roughly 45 minutes behind schedule. That rests on 297 flights, with a median arrival 5 minutes early.
The national on-time rate over the same period is 77.6%, so UA 1561 runs 7 points behind the country as a whole. Across a thousand flights that is about 66 extra late arrivals.
Key figures
On time
71.0%
Arrivals under 15 minutes late, of 297 completed flights
Avg delay
43 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
5.4%
National rate is 8.1%
These figures cover 297 flights between July 2025 and June 2026. The median arrival is 5 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 1561 flies
UA 1561 flies DEN to SFO without a single fixed slot. Its most common scheduled departure was 11:35, used on 80 of 297 flights, with 11:21 (58 flights) and 11:25 (50 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 11:3580 flights26.9%
- Departs 11:2158 flights19.5%
- Departs 11:2550 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 11:35 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1561 runs 8 points worse at 71.0%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 1561 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 1561 is 5 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 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1561thin sample | 297 | 71.0% | 43 min | 0.00% | C+ |
| 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 1561 quarter by quarter
UA 1561 did not run the same all year. Its best quarter was Jan–Mar 2026 at 81.1% on time and its weakest Apr–Jun 2026 at 54.9%, a swing of 26 points on roughly 74 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 202549 flights79.6%
- Oct–Dec 202567 flights73.1%
- Jan–Mar 202690 flights81.1%
- Apr–Jun 202691 flights54.9%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1561 did best on Saturday at 76.2% on time and worst on Monday at 62.8%. Each day rests on about 42 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 1561 runs late
One category carries most of the weight here. National Airspace System accounts for 62% of the 3,677 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.
- 62%National Airspace System
- 20%Late-arriving aircraft
- 19%Carrier
62% 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 2,266 minutes out of 3,677, against a national NAS share of 21%. The split is drawn from 3,677 delay minutes reported on UA 1561.
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
5.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 45 minutes, which a normal layover absorbs.
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 seven other city pairs in the data, including SFO to PHX (226), SFO to ONT (76) and SFO to SAN (41), but none flew often enough under UA 1561 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. 297 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 1561
For a booking, read UA 1561 as 71.0% on time with 0.00% cancelled over 297 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 1812 on the same route75.3%
- United Airlines 1007 on the same route67.6%
- 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
- 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.