69% of BOS → SEA flights arrived on time in June-August 2026 (890 flights). The most reliable was DL 384, on time 80% of the time on this route. Morning flights did best (77%), evening flights worst (56%). Boston Logan (BOS): no delay reported. Seattle (SEA): no delay reported.
Best time of day to fly BOS → SEA
| Morning (before noon) | |
| Afternoon (noon-5 PM) | |
| Evening (after 5 PM) |
Flights BOS → SEA, most reliable first
| Flight | Departs | On time on this route | Cancelled |
|---|---|---|---|
| DL 384 Delta | 7:45 AM | 2.2% | |
| B6 397 JetBlue | 7:10 AM | 0% | |
| DL 2889 Delta | 3:40 PM | 0% | |
| AS 459 Alaska Airlines | 7:03 AM | 0% | |
| DL 332 Delta | 11:29 AM | 3.3% | |
| AS 1506 Alaska Airlines | 3:26 PM | 0% | |
| AS 338 Alaska Airlines | 9:00 AM | 2.2% | |
| DL 324 Delta | 7:35 PM | 2.2% | |
| AS 306 Alaska Airlines | 7:59 PM | 0% | |
| AS 1337 Alaska Airlines | 7:44 PM | 4.2% | |
| AS 304 Alaska Airlines | 5:56 PM | 1.2% | |
| B6 197 JetBlue | 7:29 PM | 4.9% |
BOS conditions · SEA conditions · SEA → BOS · Cancellations
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From BTS on-time data, June-August 2026; flights with 20+ trips on this route. On-time rates cover each flight number's whole day, which can include other legs. Departure times are local.