Flight number record
UA 2179
United Airlines · San Francisco to Los Angeles
- Route
- SFO → LAX
- Departs
- 22:59
- Flights
- 323
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2179, check with United Airlines.
UA 2179 sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.3%. The late ones land about 50 minutes behind schedule. That rests on 323 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.3%, so UA 2179 runs 9 points behind the country as a whole. Across a thousand flights that is about 88 extra late arrivals.
Key figures
On time
68.5%
Arrivals under 15 minutes late, of 321 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.89%
1 hour+ late
8.7%
National rate is 8.3%
These figures cover 323 flights between September 2025 and August 2026. Beyond the headline rate, 8.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 2179 flies
UA 2179 flies SFO to LAX without a single fixed slot. Its most common scheduled departure was 22:59, used on 90 of 323 flights, with 22:37 (68 flights) and 22:35 (48 flights) next.
- Departs 22:5990 flights27.9%
- Departs 22:3768 flights21.1%
- Departs 22:3548 flights14.9%
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 22:59 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and UA 2179 runs level with that at 68.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 2179 next to SFO to LAX
Every carrier on SFO to LAX combined arrived on time 70.9% of the time across 11,437 flights, so UA 2179 is 2 points behind it. United flew 3,335 flights on the same city pair under all its flight numbers, including this one, and those ran 77.7% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2179thin sample | 323 | 68.5% | 49 min | 0.62% | C+ |
| All United Airlines on SFO–LAX | 3,335 | 77.7% | 46 min | 0.15% | B+ |
| All carriers on SFO–LAX | 11,437 | 70.9% | 58 min | 0.82% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 2179 quarter by quarter
UA 2179 did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.7% on time and its weakest Jul–Sep 2026 at 53.6%, a swing of 33 points on roughly 65 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 flights86.7%
- Oct–Dec 202566 flights69.7%
- Jan–Mar 202682 flights78.0%
- Apr–Jun 202688 flights62.1%
- Jul–Sep 202657 flights53.6%
Scale runs 45% to 90%.
By weekday, UA 2179 did best on Tuesday at 87.5% on time and worst on Sunday at 53.1%. Each day rests on about 46 flights, so a gap of 34 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2179 runs when it is late
The 101 late arrivals split 43 under half an hour, 30 between 30 and 60 minutes, and 28 an hour or more.
- 15+ min early77 flights24.0%
- Within 15 min143 flights44.5%
- 15–29 min late43 flights13.4%
- 30–59 min late30 flights9.3%
- 1–2 hours late22 flights6.9%
- 2+ hours late6 flights1.9%
Scale runs 0% to 100%.
Share of 321 completed flights by arrival against schedule.
21 of 108 late departures made up the time and arrived on time, 19% of them. 14 flights left on time and still arrived late.
The worst days
Worst days for UA 2179
The latest arrival of the period was on 2 January 2026, 4 hours 12 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 January 2026 | 4 hours 12 minutes | Late-arriving aircraft |
| 15 February 2026 | 3 hours 36 minutes | Late-arriving aircraft |
| 3 January 2026 | 3 hours 27 minutes | Late-arriving aircraft |
| 28 May 2026 | 2 hours 39 minutes | Late-arriving aircraft |
| 23 July 2026 | 2 hours 23 minutes | Late-arriving aircraft |
Delay causes
Why UA 2179 runs late
Late-arriving aircraft accounts for 65% of the 4,987 delay minutes carriers reported here, and the remaining four split what is left.
- 65%Late-arriving aircraft
- 30%Carrier
- 5%National Airspace System
65% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,987 reported delay minutes here, that single category outweighs weather by 65 to one. The split is drawn from 4,987 delay minutes reported on UA 2179.
Cancellations are rare at 0.62%, 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
8.7% 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 50 minutes, which a normal layover absorbs.
UA 2179 is not only a SFO to LAX flight. It also flew ORD to SFO (318 flights, 45.9% 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. 323 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 |
|---|---|---|---|---|---|
| ORD to SFOthin sample | 318 | 45.9% | 62 min | 1.26% | F |
What to do with this
Booking UA 2179
For a booking, read UA 2179 as 68.5% on time with 0.62% cancelled over 323 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SFO to LAX, every carrier and departure
- LAX to SFO, the return direction
- Delta Air Lines 1598 on the same route93.4%
- Delta Air Lines 1421 on the same route89.7%
- Delta Air Lines 2267 on the same route49.2%
- United Airlines 1754 on the same route71.8%
- Delta Air Lines 1715 on the same route56.1%
- United Airlines 1164 on the same route73.7%
- San Francisco International (SFO) delay statistics
- Los Angeles International (LAX) 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.