Best time to fly out of Seattle Tacoma (SEA)
The early-flight folk wisdom holds up at Seattle Tacoma: departures in the 6–8am band left on time 90.2% of the time, against 74.7% in the 8–10pm band. These are historical odds, not forecasts. The records say what happened on this schedule over three years; they know nothing about tomorrow’s thunderstorm.
Data through June 2026 · Bureau of Transportation Statistics
On-time rate by hour and day
On this page, “on time” means a departure that pushed back less than 15 minutes behind its scheduled time — the Bureau of Transportation Statistics definition, and the one airlines are held to.
| Departure time | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|---|
| Before 6am | 89 | 89 | 91 | 91 | 89 | 88 | 91 |
| 6–8am | 90 | 91 | 91 | 91 | 90 | 89 | 89 |
| 8–10am | 84 | 87 | 87 | 85 | 84 | 85 | 84 |
| 10am–12pm | 76 | 79 | 79 | 77 | 75 | 77 | 75 |
| 12–2pm | 78 | 81 | 80 | 78 | 75 | 77 | 76 |
| 2–4pm | 77 | 81 | 81 | 77 | 76 | 79 | 75 |
| 4–6pm | 76 | 81 | 81 | 73 | 73 | 79 | 73 |
| 6–8pm | 76 | 82 | 81 | 75 | 74 | 80 | 74 |
| 8–10pm | 75 | 81 | 79 | 70 | 72 | 78 | 70 |
| 10pm–12am | 74 | 81 | 79 | 73 | 72 | 76 | 70 |
The steadiest stretch at SEA was 6–8am — 90.2% of departures left on time across 61,777 flights. The weakest was 8–10pm at 74.7%. 6–8am departures from SEA left on time 90.2% of the time across 61,777 flights; 6–8pm departures, 77.3% across 49,620. That is a gap of 12.9 points, and it is the whole case for the early flight.
The year at SEA
June was the hard month at SEA: 73.2% of departures left on time, across 46,280 flights. October was the easy one at 85%. Each month pools three years of that month, so a single bad week does not decide it.
| Month | Share departures that left on time | Flights |
|---|---|---|
| January | 79.2% | 35,560 |
| February | 83.3% | 32,840 |
| March | 80% | 38,034 |
| April | 83% | 38,504 |
| May | 79.2% | 43,532 |
| June | 73.2% | 46,280 |
| July | 74.7% | 48,441 |
| August | 77.3% | 47,928 |
| September | 82.6% | 44,398 |
| October | 85% | 41,935 |
| November | 84.9% | 38,186 |
| December | 78.7% | 38,355 |
Airlines at SEA
Every airline with at least 100 departures from SEA, busiest first. These are that airline’s departures from this airport only — its record across the country sits on its own page.
| Airline | Left on time | Typical delay | Cancelled | Departures |
|---|---|---|---|---|
| Alaska Airlines | 77.2% | 45 min | 1% | 233,099 |
| Delta Air Lines | 84.1% | 69 min | 0.7% | 96,776 |
| SkyWest Airlines | 86.3% | 61 min | 0.5% | 82,238 |
| United Airlines | 83.3% | 79 min | 1.1% | 26,945 |
| Southwest Airlines | 69% | 47 min | 0.3% | 24,316 |
| American Airlines | 77.2% | 91 min | 1.6% | 18,250 |
| Frontier Airlines | 73.1% | 82 min | 1.7% | 4,288 |
| Hawaiian Airlines | 68% | 77 min | 1.5% | 2,813 |
| JetBlue Airways | 59.4% | 94 min | 1.5% | 2,163 |
| Spirit Airlines | 74.5% | 65 min | 0.9% | 1,771 |
| Envoy Air | 83% | 80 min | 0% | 1,334 |
What delays out of SEA were put down to
Airlines file a reason with every arrival running 15 minutes late or more. Across 100,819 flights that departed SEA and ran 15 minutes late or more, the delay minutes break down with 42.3% put down to airline operations and 30% to late-arriving aircraft.
- Late-arriving aircraft 30%
- Airline operations 42.3%
- Air traffic & airport volume 22.3%
- Severe weather 5.2%
- Security 0.2%
Late-arriving aircraft is the knock-on category: the plane came in late, so it went out late again. It is why a 7am problem in Newark is still a problem in Denver at dinnertime, and why it is usually the biggest slice on the bar.
If you are connecting through SEA
Of 493,971 scheduled arrivals into SEA, 79.7% reached the gate less than 15 minutes behind schedule. Of the 94,649 arrivals that ran late, 62.9% were no more than 45 minutes behind — which is the difference between a tight connection and a new boarding pass.
Work out a specific layover — pick the airport and the minutes you have, and the tool reads the same arrival records back as a share.
Busiest routes out of SEA
Ranked by flights, with the share that arrived on time at the far end. Where a route carries enough flights for a page of its own the chip goes there; otherwise it goes to the destination airport.
- LAX 82.8% on time · 22,513 flights
- PHX 79.7% on time · 21,750 flights
- ANC 75.8% on time · 21,642 flights
- SFO 69.9% on time · 20,106 flights
- DEN 78.3% on time · 19,613 flights
- LAS 77.7% on time · 18,738 flights
- ORD 77.6% on time · 15,693 flights
- PDX 80.8% on time · 15,623 flights
- GEG 80.5% on time · 15,597 flights
- DFW 76.4% on time · 15,129 flights
SEA in one number
Seattle Tacoma (SEA)
Rank 9 of 363 US airports by departures. Steadiest stretch of the day: 6–8am. Hardest month: June.
Questions about SEA
- What is the best time of day to fly out of Seattle Tacoma?
- 6–8am. Departures in that band left on time 90.2% of the time across 61,777 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 8–10pm band was the weakest at 74.7%.
- Is the early flight out of SEA really more reliable?
- 6–8am departures from SEA left on time 90.2% of the time across 61,777 flights; 6–8pm departures, 77.3% across 49,620. That is a gap of 12.9 points, and it is the whole case for the early flight.
- What is the worst month to fly out of SEA?
- June: 73.2% of the departures that flew left on time, with 46,280 scheduled. October was the other end of the year at 85%. Each figure pools three years of that calendar month.
- Which airline is most on time at SEA?
- SkyWest Airlines — 86.3% of its 82,238 departures from SEA left on time. JetBlue Airways sat at the other end at 59.4% over 2,163 flights. Only airlines with at least 100 departures here are ranked.
- How often are flights cancelled at SEA?
- 0.9% of scheduled departures were cancelled over July 2023 through June 2026. Cancellations are counted against everything scheduled, not against everything that flew — a rate that looks small still adds up to real people in a rebooking line.