Carrier route record

OODEN→SAN

SkyWest Airlines · Denver to San Diego

Flights: 343
Period: July 2025 to June 2026
Share of route: 6%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.

SkyWest on DEN to SAN sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about 40 minutes behind schedule. That rests on 343 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 433 at 82.9% on time.

Alaska Airlines is the most reliable of the four carriers covered here at 82.9% on time across 433 flights.

On time

75.0%

Arrivals under 15 minutes late, of 340 completed flights

Avg delay

40 min

Across delayed arrivals only, not all flights

Cancelled

0.87%

National rate is 1.81%

Whole route

75.6%

Every carrier on DEN to SAN, 5,949 flights

These figures cover 343 flights between July 2025 and June 2026. The median arrival is 5 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.

Carrier by carrier

SkyWest against every carrier on DEN to SAN

SkyWest flew 343 of the 5,949 flights on DEN to SAN, about 6% of it. Its 75.0% on time is about level with the route as a whole at 75.6%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Alaska at 82.9% to Southwest at 69.5%.

The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 82.9% of the time; Southwest Airlines manages 69.5%. Sample sizes sit next to every figure, because a two-point gap across 2,389 flights means less than a ten-point one.

On-time performance by carrier on DEN to SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlines	433	82.9%	56 min	1.15%	B
United Airlines	2,081	79.8%	59 min	0.48%	B+
Frontier Airlines	703	79.6%	63 min	0.85%	B+
SkyWest Airlines (this page)thin sample	343	75.0%	40 min	0.87%	B+
Southwest Airlines	2,389	69.5%	55 min	0.63%	C+

The spread between Alaska and Southwest is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 53 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am110 flights92.7%
8am–11am78 flights84.2%
11am–2pm38 flights73.7%
2pm–5pm28 flights—
5pm–8pm18 flights—
8pm–5am71 flights39.4%

Scale runs 30% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 39.4% on time, against 92.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 110 flights scheduled in it.

Across the year

SkyWest on DEN to SAN through the year

Oct–Dec 2025118 flights65.5%
Jan–Mar 202681 flights93.8%
Apr–Jun 2026144 flights72.0%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 75.0% on time across 343 flights.

SkyWest on DEN to SAN did not run the same all year. Its best quarter was Jan–Mar 2026 at 93.8% on time and its weakest Oct–Dec 2025 at 65.5%, a swing of 28 points on roughly 114 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.

Across the week, Tuesday is the strongest day at 84.8% on time and Thursday the weakest at 68.1%. 17 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. National Airspace System accounts for 45% of the 3,414 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

National Airspace System
45%
Late-arriving aircraft
26%
Carrier
26%
Extreme weather
3%

45% 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 1,531 minutes out of 3,414, against a national NAS share of 21%. The split is drawn from 3,414 reported delay minutes.

Cancellations are rare at 0.87%, below the national 1.81% 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 stage length

What a delay here costs

Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 79.2% on time across 342 flights, 4 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.

One caution: this is a thin sample. 343 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 SkyWest on DEN to SAN

Put together: treat all of this as provisional. 343 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 75.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 340 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures