Route reliability record
SNA→SEA
Santa Ana to Seattle
- Flights
- 3,965
- Period
- July 2025 to June 2026
- Distance
- 978 mi
- Carriers
- 3
This route earns a 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 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 3,965 flights, of which Alaska Airlines flew 2,606 at 87.5% on time.
Alaska Airlines is the most reliable of the three carriers covered here at 87.5% on time across 2,606 flights.
Key figures
On time
85.7%
Arrivals under 15 minutes late, of 3,911 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
1.21%
National rate is 1.81%
Best carrier
Alaska
87.5% on time across 2,606 flights
These figures cover 3,965 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
Which airline is most reliable on SNA to SEA
The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 87.5% of the time; Delta Air Lines manages 81.2%. Sample sizes sit next to every figure, because a two-point gap across 954 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 2,606 | 87.5% | 50 min | 1.34% | A |
| SkyWest Airlines | 405 | 84.5% | 40 min | 0.25% | B+ |
| Delta Air Lines | 954 | 81.2% | 73 min | 1.26% | B |
Alaska leads Delta by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am674 flights91.9%
- 8am–11am810 flights91.0%
- 11am–2pm685 flights86.8%
- 2pm–5pm668 flights81.0%
- 5pm–8pm896 flights76.6%
- 8pm–5am232 flights94.1%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 94.1% on time across 232 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 5pm–8pm window is the busiest, with 896 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 17 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
August is the worst month at 74.9% on time, 17 points below November, the best at 92.0%. 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 378 flights.
Across the week, Saturday is the strongest day at 89.8% on time and Sunday the weakest at 82.8%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 31,000 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.
- 44%Late-arriving aircraft
- 37%Carrier
- 18%National Airspace System
- 2%Extreme weather
44% 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 31,000 reported delay minutes here, that single category outweighs weather by 29 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 31,338 reported delay minutes.
The largest share of delay minutes, 37%, 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 12,000 of the 31,000 delay minutes reported here.
Cancellations sit at 1.21% against a national 1.81%, which is ordinary. Diversions add another 0.15%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 3.4% 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 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 85.1% on time across 3,967 flights, within half 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 3,965 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 92.0% on time and August 74.9%, a swing of 17 points. If the dates move at all, move them out of August before you think about anything else. 3,911 completed flights over 12 months sit behind that.
Common questions
SNA to SEA questions
How often is SNA to SEA delayed?
About one flight in seven arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.3% of the 3,965 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on SNA to SEA?
Alaska Airlines leads at 87.5% on time across 2,606 flights. Delta Air Lines is at the other end on 81.2%, a gap of 6 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on SNA to SEA?
The 8pm–5am departure window is the strongest at 94.1% on time. The 5pm–8pm window is the weakest at 76.6%, 18 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on SNA to SEA?
August is the weakest month at 74.9% on time, compared with 92.0% in November. Across the year that is 17 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SEA to SNA — the return legseparate record
- John Wayne Airport (SNA) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on-time record87.5%
- SkyWest Airlines on-time record84.5%
- Delta Air Lines on-time record81.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SNA to SEA and SEA to SNA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.