Carrier route record

DLSEA→SNA

Delta Air Lines · Seattle to Santa Ana

Flights: 954
Period: July 2025 to June 2026
Share of route: 24%
Carriers: 3

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

Delta on SEA to SNA lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 954 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 2,608 at 86.3% on time.

Set against the rest of the country, Delta's SEA to SNA record is 5 points better than the US average of 77.6%. That gap is worth roughly 54 fewer late arrivals for every thousand flights.

On time

83.0%

Arrivals under 15 minutes late, of 942 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

0.94%

National rate is 1.81%

Whole route

85.1%

Every carrier on SEA to SNA, 3,967 flights

These figures cover 954 flights between July 2025 and June 2026. The median arrival is 8 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

Delta against every carrier on SEA to SNA

Delta flew 954 of the 3,967 flights on SEA to SNA, about 24% of it. Its 83.0% on time is 2 points worse than the route as a whole, which runs 85.1%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Alaska at 86.3% to SkyWest at 82.4%.

The two carriers here are closely matched: 4 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on SEA to SNA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlines	2,608	86.3%	39 min	1.15%	A
Delta Air Lines (this page)	954	83.0%	77 min	0.94%	B+
SkyWest Airlines	405	82.4%	36 min	0.25%	B+

No carrier stands out. Alaska tops the table at 86.3%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Flight by flight

Delta flight numbers on SEA to SNA

DL 210107:2087.7% · 256 flights

Departure window

When Delta runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 954 flights.

5am–8am280 flights87.6%
8am–11am141 flights79.3%
11am–2pm112 flights78.4%
2pm–5pm233 flights81.4%
5pm–8pm188 flights83.8%
8pm–5am—

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 78.4% on time against 87.6% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 280 flights scheduled in it.

Across the year

Delta on SEA to SNA through the year

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

June is the worst month at 71.4% on time, 18 points below April, the best at 89.5%. 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. October was the busiest month here, with 93 flights.

Across the week, Saturday is the strongest day at 85.6% on time and Friday the weakest at 80.9%. 5 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 62% of the 12,000 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.

Carrier
62%
Late-arriving aircraft
21%
National Airspace System
17%

The largest share of delay minutes, 62%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 7,708 of the 12,000 delay minutes reported here. The split is drawn from 12,352 reported delay minutes.

Cancellations sit at 0.94% against a national 1.81%, which is ordinary. Diversions add another 0.31%.

Connections and stage length

What a delay here costs

6.7% 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 a little over an hour, which a normal layover absorbs.

The 978 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 81.2% on time across 954 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 954 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 Delta on SEA to SNA

Put together: treat all of this as provisional. 954 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 83.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 942 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