Today looks rough: weather pushes the average chance of arriving 15+ min late to 39%, against 27% on a calm day. Safest: DL 2508 at 07:15, 21%.

Safest bet today DL 2508 SEA 07:15 → SAN 10:11 · 21% chance 15+ min late · usually 91% on time Riskiest AS 1346 SEA 11:26 → SAN 14:18 · 63% chance 15+ min late · usually 55% on time

Weather 39% average chance a nonstop arrives 15+ min late; 27% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, with each flight’s on-time record over Aug 2025 – Jul 2026 beside it. Times are local. Pick a flight for its forecast. Click a column to sort.


DL 2508 Delta Flight history →	SEA 07:15	SAN 10:11	21%	5%	0.6%	91%worse than usual
AS 1361 Alaska Flight history →	SEA 06:21	SAN 09:10	21%	5%	1.3%	89%worse than usual
DL 2672 Delta Flight history →	SEA 19:40	SAN 22:34	26%	4%	0.9%	75%
DL 2572 Delta Flight history →	SEA 12:14	SAN 15:16	28%	7%	0.5%	82%
WN 3763 Southwest	SEA 07:40	SAN 10:29	31%	6%	0.3%	no record
DL 2613 Delta Flight history →	SEA 15:15	SAN 18:05	33%	7%	0.5%	84%worse than usual
AS 1401 Alaska	SEA 07:04	SAN 09:53	33%	8%	1.3%	no record
AS 1398 Alaska Flight history →	SEA 20:15	SAN 23:11	34%	5%	0.8%	64%
DL 2533 Delta Flight history →	SEA 09:45	SAN 12:39	35%	7%	0.6%	82%worse than usual
AS 600 Alaska	SEA 21:08	SAN 23:54	35%	4%	0.8%	no record
AS 1348 Alaska Flight history →	SEA 16:45	SAN 19:36	36%	5%	0.7%	60%
AS 623 Alaska Flight history →	SEA 19:07	SAN 21:53	36%	5%	0.8%	73%
AS 336 Alaska Flight history →	SEA 19:06	SAN 22:07	37%	6%	0.8%	29%
AS 791 Alaska	SEA 16:54	SAN 19:42	37%	5%	0.7%	no record
AS 254 Alaska Flight history →	SEA 20:07	SAN 22:53	37%	5%	0.8%	72%
WN 3285 Southwest	SEA 17:10	SAN 19:58	46%	9%	0.6%	no record
WN 4910 Southwest Flight history →	SEA 14:25	SAN 17:20	48%	9%	0.2%	41%
AS 621 Alaska Flight history →	SEA 11:33	SAN 14:22	49%	12%	1.1%	82%worse than usual
AS 765 Alaska Flight history →	SEA 14:59	SAN 17:47	51%	14%	1.1%	78%worse than usual
AS 1432 Alaska Flight history →	SEA 14:23	SAN 17:17	52%	14%	1.1%	69%worse than usual
AS 1367 Alaska Flight history →	SEA 08:51	SAN 11:39	52%	18%	1.2%	91%worse than usual
AS 650 Alaska Flight history →	SEA 10:20	SAN 13:09	60%	22%	1.2%	81%worse than usual
AS 1346 Alaska Flight history →	SEA 11:26	SAN 14:18	63%	22%	1.3%	55%worse than usual

How these are worked out. Each flight’s odds are our forecast for that day; flights of airlines we don’t forecast yet use their 12-month record and are marked. Makes the connection: the first flight’s 12-month lateness curve, scaled so its chance of arriving 15+ min late matches the day’s forecast, at the layover minus the 45-minute minimum (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled × second flight within 15 minutes, each from the day’s forecast.

About this data: forecast odds from our model for Mon, Oct 5 (newest published update); 12-month records from US DOT on-time data, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. JSON