Flight number record
UA 1940
United Airlines · Denver to San Diego
- Route
- DEN → SAN
- Departs
- 11:15
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1940, check with United Airlines.
UA 1940 lands a B+, about a point better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That rests on 365 flights, with a median arrival 4 minutes early.
Key figures
On time
78.4%
Arrivals under 15 minutes late, of 365 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
4.1%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 4 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.
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Schedule
When UA 1940 flies
UA 1940 flies DEN to SAN without a single fixed slot. Its most common scheduled departure was 11:15, used on 124 of 365 flights, with 11:24 (56 flights) and 11:33 (55 flights) next.
- Departs 11:15124 flights34.0%
- Departs 11:2456 flights15.3%
- Departs 11:3355 flights15.1%
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 11:15 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and UA 1940 runs level with that at 78.4%. 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 1940 next to DEN to SAN
Every carrier on DEN to SAN combined arrived on time 73.8% of the time across 6,152 flights, so UA 1940 is 5 points ahead of it. United flew 2,067 flights on the same city pair under all its flight numbers, including this one, and those ran 77.9% on time. Across its whole network United Airlines managed 78.8%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1940 | 365 | 78.4% | 49 min | 0.00% | B+ |
| All United Airlines on DEN–SAN | 2,067 | 77.9% | 59 min | 0.34% | B+ |
| All carriers on DEN–SAN | 6,152 | 73.8% | 56 min | 0.83% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1940 quarter by quarter
UA 1940 did not run the same all year. Its best quarter was Jan–Mar 2026 at 87.8% on time and its weakest Jul–Sep 2026 at 62.9%, a swing of 25 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 flights87.8%
- Apr–Jun 202691 flights76.9%
- Jul–Sep 202662 flights62.9%
Scale runs 55% to 95%.
By weekday, UA 1940 did best on Monday at 94.3% on time and worst on Friday at 63.5%. Each day rests on about 52 flights, so a gap of 31 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1940 runs when it is late
UA 1940 often beats the schedule: 93 of 365 completed flights, 25%, arrived 15 minutes or more early. The 79 late arrivals split 24 under half an hour, 40 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early93 flights25.5%
- Within 15 min193 flights52.9%
- 15–29 min late24 flights6.6%
- 30–59 min late40 flights11.0%
- 1–2 hours late9 flights2.5%
- 2+ hours late6 flights1.6%
Scale runs 0% to 100%.
Share of 365 completed flights by arrival against schedule.
9 of 70 late departures made up the time and arrived on time, 13% of them. 18 flights left on time and still arrived late.
The worst days
Worst days for UA 1940
The latest arrival of the period was on 19 December 2025, 4 hours 29 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 19 December 2025 | 4 hours 29 minutes | Late-arriving aircraft |
| 1 January 2026 | 2 hours 41 minutes | National Airspace System |
| 18 September 2025 | 2 hours 37 minutes | National Airspace System |
| 25 February 2026 | 2 hours 24 minutes | Late-arriving aircraft |
| 27 August 2026 | 2 hours 14 minutes | Late-arriving aircraft |
Delay causes
Why UA 1940 runs late
National Airspace System accounts for 54% of the 3,845 delay minutes carriers reported here, and the remaining four split what is left.
- 54%National Airspace System
- 26%Late-arriving aircraft
- 21%Carrier
54% 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 2,059 minutes out of 3,845, against a national NAS share of 21%. The split is drawn from 3,845 delay minutes reported on UA 1940.
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
Badly late arrivals are rare here: only 4.1% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 853 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 five other city pairs in the data, including XNA to DEN (35), FLL to DEN (24) and LGA to DEN (21), but none flew often enough under UA 1940 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to SAN 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 1940
For a booking, read UA 1940 as 78.4% 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 SAN, every carrier and departure
- SAN to DEN, the return direction
- United Airlines 540 on the same route63.5%
- United Airlines 1302 on the same route83.6%
- United Airlines 2309 on the same route90.9%
- United Airlines 1281 on the same route83.3%
- Frontier Airlines 4989 on the same route73.6%
- Denver International (DEN) delay statistics
- San Diego International (SAN) 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.