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Route on-time record

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

Seattle (Seattle–Tacoma International Airport) to Baltimore (Baltimore/Washington International Thurgood Marshall Airport). 718 nonstop flights in Jun 2025 to May 2026, 81% arrived within 15 minutes and 0.4% were cancelled. The most reliable flight number was Alaska 763 at 9:32 PM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

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SEA → BWI

Seattle to Baltimore: 718 nonstop flights a year

On time (12 months)

81%

Cancelled

0.4%

avg delay 9 min

Best time to leave

No clear winner

Most reliable airline

Alaska

82% chance on time

Check SEA to BWI fares

Lowest nonstop fare seen in the next two months: $212 (Alaska 781 on 2026-11-15). 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 763

    9:32 PM → 5:44 AM5h 12m nonstop

    Local times, typical schedule. Last flown 2026-05-11.

    86%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (15 flights, Jun 2025 to May 2026).
    • Departs inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.

    Limited track record · 15 flights

    Find Alaska 763 fares Opens this date on Aviasales

  2. #2 · Alaska 378

    9:59 AM → 6:04 PM5h 05m nonstop

    Local times, typical schedule. Last flown 2026-05-12.

    82%

    chance on time

    On time (history)
    82%
    Cancelled
    0.6%
    Avg arrival delay
    8 min
    • Arrived on time 82% of the time (341 flights, Jun 2025 to May 2026).
    • Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
    • Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.

    Strong track record · 341 flights

    Find Alaska 378 fares Opens this date on Aviasales

  3. #3 · Alaska 344

    10:20 PM → 6:28 AM5h 08m nonstop

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

    81%

    chance on time

    On time (history)
    81%
    Cancelled
    0.5%
    Avg arrival delay
    10 min
    • Arrived on time 81% of the time (217 flights, Jun 2025 to May 2026).
    • Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).

    Strong track record · 217 flights

    Find Alaska 344 fares Opens this date on Aviasales

  4. #4 · Alaska 379

    10:20 AM → 6:35 PM5h 15m nonstop

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

    81%

    chance on time

    On time (history)
    84%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 84% of the time (19 flights, Jun 2025 to May 2026).
    • Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
    • Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.

    Limited track record · 19 flights

    Find Alaska 379 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Alaska Airlines82%

    599 flights · 82% on time as flown · 0.5% cancel

On time by departure time

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

  • 9 AM to noon82%

    365 flights · avg delay 8 min

  • After 9 PM79%

    353 flights · avg delay 10 min

Best day: Tuesday (85%). Worst: Sunday (73%).

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
78
F
88
M
72
A
82
M
71
J
76
J
75
A
75
S
82
O
86
N
88
D
83

What delays this route

  • Airline (crew, maintenance, boarding)44%
  • Late-arriving aircraft34%
  • Air traffic control and airport volume19%
  • Severe weather4%

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 SEA to BWI…

SEA to BWI questions

Which airline is most on time from SEA to BWI?
Alaska, with a season-adjusted 82% 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 SEA to BWI?
May (71% on time); the best was February (88%), 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.

More routes from SEA

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Live status: FAA delays and ground stops