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Route on-time record

BWI to SEA: most on-time flights and the best time to fly

Baltimore (Baltimore/Washington International Thurgood Marshall Airport) to Seattle (Seattle–Tacoma International Airport). 718 nonstop flights in Jun 2025 to May 2026, 68% arrived within 15 minutes and 0.7% were cancelled. The most reliable flight number was Alaska 764 at 7:04 AM.

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BWI → SEA

Baltimore to Seattle: 718 nonstop flights a year

On time (12 months)

68%

Cancelled

0.7%

avg delay 18 min

Best time to leave

Before 9 AM

77% on time vs 51% noon to 3 PM

Most reliable airline

Alaska

67% chance on time

Check BWI to SEA fares

Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · Alaska 764

    7:04 AM → 9:51 AM5h 47m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    79%

    chance on time

    On time (history)
    87%
    Cancelled
    0.0%
    Avg arrival delay
    5 min
    • Arrived on time 87% of the time (39 flights, Jun 2025 to May 2026).
    • Never cancelled in 39 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 77% on time; Noon to 3 PM: 51%).
    • Departs outside BWI's trouble window (2 PM to 8 PM, when 81% of its 43 ground stops and delay programs started).

    Limited track record · 39 flights

    Find Alaska 764 fares Opens this date on Aviasales

  2. #2 · Alaska 379

    7:04 PM → 9:58 PM5h 54m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    61%

    chance on time

    On time (history)
    61%
    Cancelled
    0.6%
    Avg arrival delay
    18 min
    • Arrived on time 61% of the time (333 flights, Jun 2025 to May 2026).
    • Departs inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
    • Lands inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.

    Strong track record · 333 flights

    Find Alaska 379 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Alaska Airlines67%

    599 flights · 67% on time as flown · 0.8% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM77%

    277 flights · avg delay 13 min

  • Noon to 3 PM51%

    51 flights · avg delay 51 min

  • 6 to 9 PM63%

    364 flights · avg delay 17 min

Best day: Tuesday (73%). Worst: Friday (62%).

Smarter routing

Nearby airports that run more on time

  • IAD → SEA 75% chance on time

    Washington Dulles International Airport to Seattle–Tacoma International Airport · 1,926 flights a year · 45 mi from your airports · yours: 67%

    Rank flightsFares

  • DCA → SEA 72% chance on time

    Ronald Reagan Washington National Airport to Seattle–Tacoma International Airport · 1,094 flights a year · 30 mi from your airports · yours: 67%

    Rank flightsFares

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
63
F
79
M
57
A
64
M
67
J
53
J
61
A
78
S
78
O
86
N
77
D
59

What delays this route

  • Air traffic control and airport volume37%
  • Late-arriving aircraft33%
  • Airline (crew, maintenance, boarding)17%
  • Severe weather11%
  • Security1%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

Finding the most reliable connections from BWI to SEA…

BWI to SEA questions

What time of day is best to fly BWI to SEA?
Before 9 AM: 77% of flights arrived on time, against 51% for departures noon to 3 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from BWI to SEA?
Alaska, with a season-adjusted 67% chance of operating and arriving on time over 599 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on BWI to SEA?
June (53% on time); the best was October (86%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

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Live status: FAA delays and ground stops