FlightRecord

Seattle–Tacoma International Airport (SEA): Delays & On-Time Performance

Data through May 2026

Seattle–Tacoma International Airport (SEA) in Seattle, WA is a middle-of-the-pack performer: 79% of departures are on time, within a few points of the national 78%. It hosts 11 airlines flying 453 departures a day to 97 destinations, with cancellations at 0.8%.

Departures on-time
79%
left <15 min late
Avg dep delay
13 min
Arrivals on-time
80%
Cancelled
0.8%
Destinations
97
nonstop
Airlines
11

Monthly on-time trend

Monthly departure on-time percentage at SEA50%75%100%June 2024: 73% on-time (15,183 flights)73Jun 2024July 2024: 75% on-time (16,198 flights)75August 2024: 76% on-time (15,984 flights)76September 2024: 81% on-time (14,805 flights)81Sep 2024October 2024: 86% on-time (13,763 flights)86November 2024: 87% on-time (12,453 flights)87December 2024: 80% on-time (12,596 flights)80Dec 2024January 2025: 83% on-time (11,882 flights)83February 2025: 79% on-time (10,738 flights)79March 2025: 83% on-time (12,577 flights)83Mar 2025April 2025: 83% on-time (12,716 flights)83May 2025: 80% on-time (14,630 flights)80June 2025: 72% on-time (15,695 flights)72Jun 2025July 2025: 72% on-time (16,577 flights)72August 2025: 75% on-time (15,970 flights)75September 2025: 83% on-time (14,552 flights)83Sep 2025October 2025: 82% on-time (13,859 flights)82November 2025: 84% on-time (12,616 flights)84December 2025: 73% on-time (13,023 flights)73Dec 2025January 2026: 80% on-time (11,927 flights)80February 2026: 84% on-time (11,000 flights)84March 2026: 77% on-time (12,830 flights)77Mar 2026April 2026: 85% on-time (12,864 flights)85May 2026: 80% on-time (14,564 flights)80

Best time of day to depart from SEA

On-time percentage by scheduled departure hour at SEA5 a.m.: 94% on-time (5,488 flights)56 a.m.: 92% on-time (11,802 flights)67 a.m.: 90% on-time (26,646 flights)78 a.m.: 88% on-time (23,486 flights)89 a.m.: 84% on-time (24,230 flights)910 a.m.: 78% on-time (20,271 flights)1011 a.m.: 74% on-time (29,507 flights)1112 p.m.: 77% on-time (15,311 flights)121 p.m.: 78% on-time (18,432 flights)132 p.m.: 78% on-time (10,857 flights)143 p.m.: 77% on-time (22,969 flights)154 p.m.: 77% on-time (10,375 flights)165 p.m.: 76% on-time (23,140 flights)176 p.m.: 75% on-time (14,023 flights)187 p.m.: 79% on-time (19,721 flights)198 p.m.: 72% on-time (9,505 flights)209 p.m.: 76% on-time (17,617 flights)2110 p.m.: 71% on-time (11,041 flights)2211 p.m.: 75% on-time (12,873 flights)23scheduled departure hour

Busiest routes from SEA

RouteFlights/12moOn-timeAvg delay
SEA → LAX7,41083%11 min
SEA → PHX7,31779%12 min
SEA → SFO6,76172%18 min
SEA → ANC6,71775%13 min
SEA → DEN6,32578%14 min
SEA → LAS5,70377%13 min
SEA → ORD5,55576%16 min
SEA → GEG5,31780%11 min

Most reliable routes

  1. SEA → LWS90%
  2. SEA → MFR88%
  3. SEA → OKC87%
  4. SEA → JAC86%
  5. SEA → CLT86%

Most delay-prone routes

  1. SEA → SIT62%
  2. SEA → DAL68%
  3. SEA → HNL69%
  4. SEA → HOU71%
  5. SEA → SFO72%

Airline performance at SEA

AirlineOn-time departuresAvg delayFlights
SkyWest Airlines86%9 min56,613
United Airlines84%14 min17,982
Envoy Air84%13 min924
Delta Air Lines84%13 min64,040
American Airlines77%20 min12,284
Alaska Airlines77%12 min153,846
Frontier Airlines74%24 min3,107
Spirit Airlines74%17 min1,030
Southwest Airlines68%17 min15,997
Hawaiian Airlines64%30 min2,137
JetBlue Airways61%34 min1,042

Frequently asked questions

How often are flights delayed at SEA?
21% of departures from Seattle–Tacoma International Airport left 15+ minutes late between 2024-06 and 2026-05, with an average departure delay of 13 minutes. The national on-time average over the same period was 78%.
What is the best time of day to depart from SEA?
Flights scheduled around 5 a.m. depart on time 94% of the time at SEA, versus 66% around 1 a.m.. Booking before noon is the usual rule of thumb here.
What is the worst month for delays at SEA?
In this dataset, June 2025 was the weakest month at SEA, with 72% of departures on time.
How often are flights cancelled at SEA?
0.8% of scheduled departures from SEA were cancelled in this period, compared with a national rate of 1.6%.

Popular route pages from this airport

Based on 329,002 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.