FlightRecord

Seattle (SEA) to Los Angeles (LAX): On-Time Performance

Data through May 2026

Seattle (SEA) to Los Angeles (LAX) effectively runs on two schedules. In January 2025, 90% of arrivals were on time; in December 2025 that fell to 74% — a 17-point seasonal swing. Across the full period the route averages 83% on-time against a national 78%. Morning departures also hold up better than evening ones (87% vs 78%), which matters most in the rough months.

On-time
83%
arrived <15 min late
Avg delay
11 min
completed flights
Cancelled
0.8%
Flights/day
20
last 12 months
Duration
2h 49m
scheduled
Distance
954 mi

Best airline from SEA to LAX

6 airlines flew this route regularly between 2024-06 and 2026-05.

AirlineOn-timeAvg delayCancelledFlights
United Airlinesmost reliable91%10 min0.6%1,070
Spirit Airlines87%12 min1.1%276
Delta Air Lines86%9 min0.5%4,410
SkyWest Airlines84%17 min0.5%2,075
Frontier Airlines81%12 min2.9%413
Alaska Airlines80%10 min0.9%6,746

Monthly on-time trend

Monthly on-time percentage for SEA to LAX flights50%75%100%June 2024: 81% on-time (645 flights)81Jun 2024July 2024: 78% on-time (694 flights)78August 2024: 78% on-time (693 flights)78September 2024: 86% on-time (649 flights)86Sep 2024October 2024: 84% on-time (642 flights)84November 2024: 89% on-time (587 flights)89December 2024: 83% on-time (642 flights)83Dec 2024January 2025: 90% on-time (624 flights)90February 2025: 77% on-time (555 flights)77March 2025: 85% on-time (609 flights)85Mar 2025April 2025: 89% on-time (587 flights)89May 2025: 84% on-time (654 flights)84June 2025: 80% on-time (633 flights)80Jun 2025July 2025: 78% on-time (642 flights)78August 2025: 80% on-time (635 flights)80September 2025: 89% on-time (605 flights)89Sep 2025October 2025: 86% on-time (614 flights)86November 2025: 85% on-time (604 flights)85December 2025: 74% on-time (632 flights)74Dec 2025January 2026: 81% on-time (564 flights)81February 2026: 83% on-time (554 flights)83March 2026: 84% on-time (639 flights)84Mar 2026April 2026: 90% on-time (611 flights)90May 2026: 87% on-time (677 flights)87

Best time to fly from SEA to LAX

Aim for departures around 8 a.m. (90% on-time); avoid 9 p.m. departures (72%).

On-time percentage by scheduled departure hour, SEA to LAX5 a.m.: 89% on-time (260 flights)56 a.m.: 88% on-time (1,475 flights)67 a.m.: 90% on-time (1,429 flights)78 a.m.: 90% on-time (781 flights)89 a.m.: 86% on-time (777 flights)910 a.m.: 85% on-time (969 flights)1011 a.m.: 79% on-time (825 flights)1112 p.m.: 86% on-time (768 flights)121 p.m.: 81% on-time (516 flights)132 p.m.: 85% on-time (1,003 flights)143 p.m.: 82% on-time (560 flights)154 p.m.: 83% on-time (657 flights)165 p.m.: 79% on-time (1,994 flights)176 p.m.: 80% on-time (545 flights)187 p.m.: 80% on-time (1,287 flights)198 p.m.: 78% on-time (500 flights)209 p.m.: 72% on-time (644 flights)21scheduled departure hour

By day of week

DayOn-timeAvg delay
Monday84%11 min
Tuesdaybest86%8 min
Wednesday86%9 min
Thursday82%10 min
Friday82%11 min
Saturday84%11 min
Sunday81%13 min

What causes delays on this route

Share of total delay minutes by cause, as reported by carriers to the US DOT.

  • Late-arriving aircraft30%
  • Airline operations52%
  • National airspace system14%
  • Weather3%
  • Security1%

Frequently asked questions

How often are flights from SEA to LAX delayed?
17% of SEA–LAX flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 11 minutes.
Which airline is most reliable from SEA to LAX?
United Airlines has the best on-time record on this route at 91%, based on 1,070 flights. 6 airlines flew SEA–LAX frequently enough to compare in this period.
What is the best time of day to fly from SEA to LAX?
Departures around 8 a.m. have the best record (90% on-time), while departures around 9 p.m. have the worst (72%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
How long is the flight from SEA to LAX?
The scheduled SEA–LAX flight time averages 2h 49m over 954 miles. Actual arrival times vary — flights on this route land 15+ minutes late 17% of the time.
How often are SEA to LAX flights cancelled?
0.8% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
What is the worst month to fly from SEA to LAX?
December 2025 was the roughest month in this dataset, with only 74% of arrivals on time. The best was January 2025 at 90%. If your dates are flexible, that 17-point gap is worth planning around.

Based on 14,991 flights, 2024-062026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.