Carrier route record

UASNA→DEN

United Airlines · Santa Ana to Denver

Flights: 1,870
Period: July 2025 to June 2026
Share of route: 51%
Carriers: 3

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

United on SNA to DEN earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,870 flights, with a median arrival 10 minutes early.

Set against the rest of the country, United's SNA to DEN record is 9 points better than the US average of 77.6%. That gap is worth roughly 85 fewer late arrivals for every thousand flights.

On time

86.1%

Arrivals under 15 minutes late, of 1,855 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

0.37%

National rate is 1.81%

Whole route

82.4%

Every carrier on SNA to DEN, 3,697 flights

These figures cover 1,870 flights between July 2025 and June 2026. The median arrival is 10 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

United against every carrier on SNA to DEN

United flew 1,870 of the 3,697 flights on SNA to DEN, most of the route. Its 86.1% on time is 4 points better than the route as a whole, which runs 82.4%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 86.1% to Southwest at 77.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on SNA to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines (this page)	1,870	86.1%	64 min	0.37%	A+
Frontier Airlinesthin sample	292	84.9%	91 min	0.34%	B+
Southwest Airlines	1,535	77.5%	57 min	0.46%	B+

Flight by flight

United flight numbers on SNA to DEN

UA 265618:4087.1% · 276 flights

Departure window

When United runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am311 flights90.6%
8am–11am406 flights94.3%
11am–2pm687 flights83.0%
2pm–5pm190 flights71.6%
5pm–8pm276 flights87.1%
8pm–5am—

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 94.3% of the time, against 71.6% for the afternoon window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 687 flights scheduled in it.

Across the year

United on SNA to DEN through the year

Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 67.8% on time, 25 points below April, the best at 93.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 181 flights.

Across the week, Saturday is the strongest day at 90.1% on time and Thursday the weakest at 83.0%. 7 points is a smaller lever than departure hour, but it is free.

Delay causes

Why United runs late on this route

One category carries most of the weight here. National Airspace System accounts for 44% of the 16,000 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
44%
Late-arriving aircraft
39%
Carrier
14%
Extreme weather
3%

39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 16,000 reported delay minutes here, that single category outweighs weather by 14 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 16,498 reported delay minutes.

44% 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 7,248 minutes out of 16,000, against a national NAS share of 21%.

Cancellations are rare at 0.37%, 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

5.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

The 846 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 runs 84.8% on time across 1,870 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,870 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking United on SNA to DEN

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 93.1% on time and July 67.8%, a swing of 25 points. If the dates move at all, move them out of July before you think about anything else. 1,855 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