1,853 nonstop flights · Aug 2025 – Jul 2026 · US DOT on-time records, all US airlines

Leave before 9 am: 92% depart on time. After 4 pm it’s 78%.

Best time to leave 8–9 am 91% arrive on time from SEA

Best single flight AS 737 SEA 09:13 → IAD 17:11 · 84% on time Avoid DL 541 SEA 16:20 → IAD 00:25 · 77% 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

Dulles flights leaving SEA 3–4 pm: 1Close ×


AS 348	SEA 15:53	IAD 23:59	5h 06m	132	81%	0.8%	34 min

Airlines on this route

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


United	657	90%	0.8%	87 min
Alaska	835	83%	0.4%	39 min
Delta	361	77%	1.1%	78 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.


AS 737	SEA 09:13	IAD 17:11	84%
AS 367	SEA 22:43	IAD 06:39	84%
DL 541	SEA 16:20	IAD 00:25	77%

All 9 flights on this route →

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.


United	SEA	IAD	5h 07m	90%	0.8%	657	Flying now
Alaska	SEA	IAD	4h 58m	83%	0.4%	835	Flying now
Delta	SEA	IAD	5h 05m	77%	1.1%	361	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