DEN to SAN flight delays
Denver, CO (DEN) San Diego, CA (SAN) · 853 miles
525 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics
65.01%
Arrived on time
Within 15 minutes of schedule
0.38%
Cancelled
Share of scheduled flights
54 min
When late, late by
Average across delayed arrivals
20 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Which airline you fly changes the odds here. United Airlines arrived on time 18.2 points more often than Southwest Airlines over the same period on the same route — same airports, same weather, same air traffic control. A gap that survives all of that is about how the two airlines are run.
This is a late route. Flights from Denver to San Diego miss their scheduled arrival often enough that a tight connection at the far end is a connection at risk.
The two directions do not behave alike. SAN to DEN arrives on time 6.5 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
This is a thin route — 525 flights across the whole period. On a route this infrequent a cancellation is far more costly than the rate suggests, because the next departure may not be the same day.
Which airline should you fly on this route?
Over March 2025 – August 2026, United Airlines arrived on time most often on DEN to SAN. Southwest Airlines was late most often.
Every airline on DEN to SAN
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 204 | 53.69% | 0.49% | 59 min | F |
| United Airlines | 171 | 71.93% | 0% | 54 min | C |
| Frontier Airlines | 60 | 76.27% | 1.67% | 56 min | — |
| SkyWest Airlines | 48 | 56.25% | 0% | 44 min | — |
| Alaska Airlines | 42 | 85.71% | 0% | 27 min | — |
The return leg
SAN to DEN San Diego back to Denver 71.48% on time COther routes from Denver
Common questions
Are flights from Denver to San Diego usually delayed?
65.01% of flights on the DEN to SAN route arrived within 15 minutes of schedule, so roughly 3 in every ten arrived late. That is worse than the average route in this record.
Which airline is most on time from Denver to San Diego?
United Airlines, at 71.93% on time across 171 flights. The least punctual on the route was Southwest Airlines at 53.69%.
How often are DEN to SAN flights cancelled?
0.38% of scheduled flights did not operate — about 4 in every thousand. That is in the normal range.
When DEN to SAN flights are late, how late are they?
About 54 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on DEN to SAN during March 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →