BWI to SEA flight delays & on-time performance
Nonstop flights from Baltimore/Washington International Thurgood Marshall Airport to Seattle–Tacoma International Airport · 2,335 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at BWI or SEA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Baltimore (BWI) to Seattle (SEA) arrived on time 71% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 1% were cancelled, and 7% arrived an hour or more late.
- Southwest Airlines was the most punctual airline here (72% on time); Alaska Airlines was the least (71%).
- Departures scheduled around 7am did best (77% on time); around 3pm did worst (52%).
- Monday was the most reliable day to fly (75% on time) and Thursday the least (61%).
- The largest source of delay minutes was air traffic control & airport congestion (36%).
Which airline is most on time from BWI to SEA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Southwest Airlines | 72% | 0.8% | 21 min | 10.1% | 120 |
| Alaska Airlines | 71% | 1.0% | 15 min | 6.1% | 599 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 7am77%259 flights
- 8am94%18 flights
- 9am71%14 flights
- 10am73%16 flights
- 3pm52%27 flights
- 6pm67%130 flights
- 7pm66%234 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday75%1.9% cancelled
- Tuesday73%1.0% cancelled
- Wednesday72%0.0% cancelled
- Thursday61%0.0% cancelled
- Friday68%0.9% cancelled
- Saturday74%1.1% cancelled
- Sunday74%1.9% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion36%
- Late-arriving aircraft31%
- Airline (crew, maintenance, cleaning, fueling)16%
- Extreme weather15%
- Security2%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)71%
- Extreme weather29%
- Air traffic control & airport congestion0%
- Security0%
BWI to SEA: common questions
- How often are BWI to SEA flights on time?
- 71% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Baltimore to Seattle cancelled?
- 1.0% of scheduled flights were cancelled (7 of 719).
- How long are typical delays?
- Across all flights the average arrival delay was 16 min (early arrivals count as zero). Flights that were late arrived 50 min behind schedule on average, and 6.7% of flights were an hour or more late.
- How long is taxi time at BWI?
- Flights on this route spent 16 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to BWI — 80% on time
More flights from Baltimore
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: BWI → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.