BOS to SEA flight delays & on-time performance
Nonstop flights from Boston Logan International Airport to Seattle–Tacoma International Airport · 2,496 miles · Aug 2025 – Jul 2026
- BOS: Ground delay program, avg 1 hour and 10 minutes. Flights to BOS are delayed at their origin airports due to runway construction: average 1 hour and 10 minutes, up to 3 hours.
On-time arrivals
72%
arrived < 15 min late
Cancelled
1.3%
32 flights
Avg arrival delay
16 min
54 min when late
Airlines
3
2,504 flights tracked
Key facts
- Flights from Boston (BOS) to Seattle (SEA) arrived on time 72% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 1.3% were cancelled, and 7% arrived an hour or more late.
- JetBlue was the most punctual airline here (79% on time); Alaska Airlines was the least (71%).
- Departures scheduled around 4pm did best (82% on time); around 5pm did worst (59%).
- Saturday was the most reliable day to fly (76% on time) and Thursday the least (66%).
- The largest source of delay minutes was late-arriving aircraft (38%).
Which airline is most on time from BOS 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 |
|---|---|---|---|---|---|
| JetBlue | 79% | 1.2% | 16 min | 10.7% | 247 |
| Delta Air Lines | 73% | 1.4% | 17 min | 6.5% | 1,035 |
| Alaska Airlines | 71% | 1.1% | 16 min | 6.8% | 1,222 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 7am78%862 flights
- 9am76%335 flights
- 11am78%239 flights
- 3pm73%85 flights
- 4pm82%129 flights
- 5pm59%85 flights
- 6pm63%538 flights
- 7pm60%210 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday75%2.4% cancelled
- Tuesday72%1.7% cancelled
- Wednesday76%0.9% cancelled
- Thursday66%1.1% cancelled
- Friday73%0.5% cancelled
- Saturday76%0.9% cancelled
- Sunday70%1.4% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft38%
- Air traffic control & airport congestion36%
- Airline (crew, maintenance, cleaning, fueling)24%
- Extreme weather3%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)53%
- Extreme weather41%
- Air traffic control & airport congestion6%
- Security0%
BOS to SEA: common questions
- How often are BOS to SEA flights on time?
- 72% 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 Boston to Seattle cancelled?
- 1.3% of scheduled flights were cancelled (32 of 2,504).
- 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 54 min behind schedule on average, and 7.1% of flights were an hour or more late.
- How long is taxi time at BOS?
- Flights on this route spent 24 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to BOS — 75% on time
More flights from Boston
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: BOS → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.