Flight profile · United Airlines
UA2309
Denver (DEN) to San Diego (SAN) · scheduled 7:45 AM – 9:14 AM
How UA2309 performs
1,018 operations, 2023-07-01 to 2026-06-30.
UA2309 arrived on time 87.7% of the time, against 75.9% for all DEN → SAN flights — this specific departure is 11.9 percentage points better than the route as a whole. Against United Airlines’s own flights on this route it is 7.1 points better.
Source: US DOT Bureau of Transportation Statistics · 1,018 operations between 2023-07-01 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| UA2309 | 87.7% | 0.39% | -12 min | 3.3% | 1,018 |
| United Airlines on DEN → SAN | 80.6% | 0.87% | -7 min | 6.7% | 6,420 |
| All DEN → SAN flights | 75.9% | 0.98% | -4 min | 7.3% | 16,924 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30
By day of week
Does UA2309 run worse on particular days?
Tuesday is historically the most reliable day and Friday the least, a gap of 10.7 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Other routes UA2309 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| SAN→SFO San Diego to San Francisco | 2024-02-15 – 2026-06-30 | 473 | 64.8% |
| MCI→DEN Kansas City to Denver | 2026-03-29 – 2026-04-05 | 3 | — |
| MSY→DEN New Orleans to Denver | 2024-12-19 – 2025-01-06 | 16 | — |
| SFO→PDX San Francisco to Portland | 2024-03-07 – 2024-12-18 | 267 | 85.0% |
| SAT→DEN San Antonio to Denver | 2024-10-27 – 2024-10-31 | 5 | — |
| ORD→DEN Chicago to Denver | 2024-08-19 – 2024-08-31 | 13 | — |
Because the same number has served different journeys, the statistics above describe only the route UA2309 currently operates. Blending them would produce an average of two different flights.
Data and methodology
Calculated by FlyerIntel from 1,018 records of UA2309 operating DEN → SAN, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.