2,502 nonstop flights · Aug 2025 – Jul 2026 · US DOT on-time records, all US airlines

No clear winner: airlines and hours on this route all land within a few points of 3 in 4 on time.

Best time to leave 7–8 am 89% arrive on time from SEA

Best single flight DL 459 SEA 07:29 → BOS 16:00 · 88% on time Avoid B6 398 SEA 11:45 → BOS 20:13 · 55% on time

Time of day × airport

Share of this route’s flights leaving within 15 minutes, by airport and scheduled departure hour, over Aug 2025 – Jul 2026. Blank: no flights then (or fewer than 40 in the year).

SEA

% of this route’s flights leaving within 15 min (small number: flights in the Jun 6 – Jul 31, 2026 schedule): 85+75–8465–7455–64under 55

Pick an hour to see this route’s flights leaving then.

Airlines on this route

Arriving within 15 minutes. Regional flights count under the airline that sells them. Pick an airline to see its flights.


Delta	1,034	81%	1.6%	72 min
Alaska	1,221	76%	1.0%	51 min
JetBlue	247	55%	1.6%	89 min

Flights, best and worst

Flights in the Jun 6 – Jul 31, 2026 schedule that ran 150+ times in the year. Times are local. Pick a flight for its history.


DL 459	SEA 07:29	BOS 16:00	88%
DL 473	SEA 23:15	BOS 07:35	82%
AS 460	SEA 15:36	BOS 23:59	80%
AS 536	SEA 23:18	BOS 07:40	78%
AS 306	SEA 08:23	BOS 16:53	76%
· · ·
DL 474	SEA 16:00	BOS 00:21	71%
B6 398	SEA 11:45	BOS 20:13	55%

All 13 flights in the current schedule

Every flight that flew in the Jun 6 – Jul 31, 2026 schedule, with its record over Aug 2025 – Jul 2026. Times are local. Click a column to sort.


AS 1505	SEA 06:03	BOS 14:23	5h 20m	18	100%	0.0%	–
DL 459	SEA 07:29	BOS 16:00	5h 31m	365	88%	2.2%	88 min
AS 330	SEA 07:55	BOS 16:32	5h 37m	28	93%	0.0%	60 min
AS 306	SEA 08:23	BOS 16:53	5h 30m	365	76%	1.4%	58 min
AS 219	SEA 10:13	BOS 18:41	5h 28m	52	58%	0.0%	58 min
DL 438	SEA 11:15	BOS 19:43	5h 26m	49	65%	0.0%	97 min
B6 398	SEA 11:45	BOS 20:13	5h 28m	165	55%	0.6%	69 min
DL 412	SEA 12:05	BOS 20:43	5h 38m	31	90%	0.0%	74 min
AS 460	SEA 15:36	BOS 23:59	5h 23m	359	80%	1.1%	46 min
DL 474	SEA 16:00	BOS 00:21	5h 21m	226	71%	1.8%	83 min
DL 473	SEA 23:15	BOS 07:35	5h 20m	363	82%	1.4%	43 min
AS 536	SEA 23:18	BOS 07:40	5h 22m	240	78%	0.8%	38 min
B6 198	SEA 23:44	BOS 08:00	5h 18m	82	53%	3.7%	128 min

Nonstops by airline and airport

Arriving within 15 minutes, Aug 2025 – Jul 2026. Pick a row to see that airline’s flights on that airport pair.


Delta	SEA	BOS	5h 26m	81%	1.6%	1,034	Flying now
Alaska	SEA	BOS	5h 27m	76%	1.0%	1,221	Flying now
JetBlue	SEA	BOS	5h 28m	55%	1.6%	247	Flying now

Flying on a particular day? Pick a date above and the same ranking uses our forecast odds for each flight that day: Tomorrow.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON