UA540
United Airlines flight 540 — Denver (DEN) to San Diego (SAN)
On time
72%
Avg delay
~61 min
Cancelled
1.4%
UA540 is fairly reliable, though delays happen. About 72% of departures arrive on time. When delays happen, the most common cause is late-arriving aircraft.
Monthly breakdown
| Month | On time | Cancelled | Avg delay |
|---|---|---|---|
| 2026-07 | 35% | 0.0% | 52 min |
| 2026-07 | 71% | 0.0% | 44 min |
| 2026-06 | 47% | 0.0% | 47 min |
| 2026-06 | 85% | 0.0% | 136 min |
| 2026-06 | 80% | 0.0% | 86 min |
| 2026-05 | 68% | 0.0% | 51 min |
| 2026-05 | 70% | 0.0% | 26 min |
| 2026-05 | 90% | 0.0% | 26 min |
| 2026-05 | 91% | 0.0% | 140 min |
| 2026-04 | 90% | 0.0% | 56 min |
| 2026-03 | 71% | 0.0% | 77 min |
| 2026-02 | 82% | 0.0% | 37 min |
Top delay cause
late-arriving aircraft
Based on 1,799 tracked departures
Flying UA540? Get a free briefing.
Weather, delays, and what to expect — sent to your inbox before your flight.
Get a free briefingData last updated October 2026. Source: Bureau of Transportation Statistics.