SEA to BWI flight delays & on-time performance
Nonstop flights from Seattle–Tacoma International Airport to Baltimore/Washington International Thurgood Marshall Airport · 2,335 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at SEA or BWI right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Seattle (SEA) to Baltimore (BWI) arrived on time 80% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.4% were cancelled, and 3% arrived an hour or more late.
- Alaska Airlines was the most punctual airline here (84% on time); Southwest Airlines was the least (61%).
- Departures scheduled around 9am did best (87% on time); around 9pm did worst (76%).
- Saturday was the most reliable day to fly (87% on time) and Thursday the least (74%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (39%).
Which airline is most on time from SEA to BWI?
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 |
|---|---|---|---|---|---|
| Alaska Airlines | 84% | 0.5% | 7 min | 2.4% | 599 |
| Southwest Airlines | 61% | 0.0% | 16 min | 5.8% | 120 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 9am87%183 flights
- 10am79%182 flights
- 9pm76%277 flights
- 10pm80%77 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday82%0.0% cancelled
- Tuesday79%0.0% cancelled
- Wednesday81%0.0% cancelled
- Thursday74%1.0% cancelled
- Friday84%0.0% cancelled
- Saturday87%0.0% cancelled
- Sunday75%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.
- Airline (crew, maintenance, cleaning, fueling)39%
- Late-arriving aircraft36%
- Air traffic control & airport congestion22%
- Extreme weather4%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)67%
- Extreme weather33%
- Air traffic control & airport congestion0%
- Security0%
SEA to BWI: common questions
- How often are SEA to BWI flights on time?
- 80% 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 Seattle to Baltimore cancelled?
- 0.4% of scheduled flights were cancelled (3 of 719).
- How long are typical delays?
- Across all flights the average arrival delay was 9 min (early arrivals count as zero). Flights that were late arrived 39 min behind schedule on average, and 2.9% of flights were an hour or more late.
- How long is taxi time at SEA?
- Flights on this route spent 23 min taxiing from the gate to takeoff on average.
Related routes
Return trip: BWI to SEA — 71% on time
More flights from Seattle
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: SEA → BWI, nonstop flights by US airlines that report to the DOT. How we calculate this.