Flight number record
UA 2356
United Airlines · Las Vegas to San Francisco
- Route
- LAS → SFO
- Departs
- 07:45
- Flights
- 349
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2356, check with United Airlines.
UA 2356 draws a D+. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 45 minutes behind schedule. Build slack into anything you connect to. That rests on 349 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.6%, so UA 2356 runs 15 points behind the country as a whole. Across a thousand flights that is about 150 extra late arrivals.
Key figures
On time
62.6%
Arrivals under 15 minutes late, of 348 completed flights
Avg delay
43 min
Across delayed arrivals only, not all flights
Cancelled
0.29%
National rate is 1.81%
1 hour+ late
5.5%
National rate is 8.1%
These figures cover 349 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Schedule
When UA 2356 flies
UA 2356 flies LAS to SFO without a single fixed slot. Its most common scheduled departure was 07:45, used on 117 of 349 flights, with 07:30 (74 flights) and 07:15 (60 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 07:45117 flights33.5%
- Departs 07:3074 flights21.2%
- Departs 07:1560 flights17.2%
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 07:45 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 2356 runs 27 points worse at 62.6%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
UA 2356 next to LAS to SFO
Every carrier on LAS to SFO combined arrived on time 62.8% of the time across 6,060 flights, so UA 2356 is about level with it. United flew 2,756 flights on the same city pair under all its flight numbers, including this one, and those ran 67.5% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 16 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2356thin sample | 349 | 62.6% | 43 min | 0.29% | D+ |
| All United Airlines on LAS–SFO | 2,756 | 67.5% | 61 min | 0.44% | C+ |
| All carriers on LAS–SFO | 6,060 | 62.8% | 59 min | 0.68% | D+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 2356 quarter by quarter
UA 2356 did not run the same all year. Its best quarter was Jan–Mar 2026 at 80.0% on time and its weakest Oct–Dec 2025 at 55.3%, a swing of 25 points on roughly 87 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 202592 flights58.7%
- Oct–Dec 202576 flights55.3%
- Jan–Mar 202690 flights80.0%
- Apr–Jun 202691 flights55.6%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2356 did best on Saturday at 78.0% on time and worst on Thursday at 54.0%. Each day rests on about 50 flights, so a gap of 24 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 2356 runs late
One category carries most of the weight here. National Airspace System accounts for 85% of the 5,642 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.
- 85%National Airspace System
- 12%Carrier
- 3%Late-arriving aircraft
- 1%Extreme weather
85% 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 4,787 minutes out of 5,642, against a national NAS share of 21%. The split is drawn from 5,642 delay minutes reported on UA 2356.
Cancellations are rare at 0.29%, below the national 1.81% 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
5.5% 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.
UA 2356 is not only a LAS to SFO flight. It also flew SFO to BOS (328 flights, 61.6% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 349 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SFO to BOSthin sample | 328 | 61.6% | 82 min | 0.91% | D+ |
What to do with this
Booking UA 2356
For a booking, read UA 2356 as 62.6% on time with 0.29% cancelled over 349 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- LAS to SFO, every carrier and departure
- SFO to LAS, the return direction
- United Airlines 2047 on the same route70.9%
- United Airlines 574 on the same route68.5%
- Frontier Airlines 4401 on the same route52.5%
- Alaska Airlines 613 on the same route74.2%
- Alaska Airlines 634 on the same route59.1%
- Harry Reid International (LAS) 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.