Today looks rough: weather pushes the average chance of arriving 15+ min late to 50%, against 32% on a calm day. Safest: UA 1730 at 18:46, 40%.

Safest bet today UA 1730 SEA 18:46 → LAX 21:43 · 40% chance 15+ min late · usually 89% on time Riskiest AS 487 SEA 11:15 → LAX 14:01 · 67% chance 15+ min late · usually 57% on time

Weather 50% average chance a nonstop arrives 15+ min late; 32% 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. 9 flights that already left today are not shown.


UA 1730 United Flight history →	SEA 18:46	LAX 21:43	40%	9%	0.2%	89%worse than usual
AA 6438 American flown by SkyWest Flight history →	SEA 17:17	LAX 20:15	42%	8%	0.3%	84%worse than usual
AA 6324 American flown by SkyWest Flight history →	SEA 14:20	LAX 17:18	43%	7%	0.4%	72%worse than usual
AA 9732 American	SEA 18:40	LAX 21:40	43%	14%	0.4%	no record
DL 2854 Delta Flight history →	SEA 20:25	LAX 23:15	45%	14%	0.2%	78%worse than usual
DL 2512 Delta Flight history →	SEA 21:46	LAX 00:33	45%	13%	0.2%	70%worse than usual
DL 2861 Delta Flight history →	SEA 17:30	LAX 20:13	46%	11%	0.1%	76%worse than usual
OO 4796 SkyWest	SEA 16:39	LAX 19:25	47%	8%	0.4%	no record
DL 2830 Delta Flight history →	SEA 15:10	LAX 17:51	48%	9%	0.2%	85%worse than usual
AS 63 Alaska Flight history →	SEA 20:15	LAX 23:06	48%	10%	0.5%	72%worse than usual
DL 2914 Delta Flight history →	SEA 12:35	LAX 15:23	49%	10%	0.2%	86%worse than usual
OO 4729 SkyWest	SEA 12:22	LAX 15:08	51%	12%	0.5%	no record
AS 492 Alaska Flight history →	SEA 19:07	LAX 21:47	53%	11%	0.5%	78%worse than usual
AS 524 Alaska Flight history →	SEA 21:09	LAX 23:52	53%	11%	0.5%	82%worse than usual
OO 4988 SkyWest	SEA 13:07	LAX 15:53	55%	12%	0.4%	no record
AS 696 Alaska Flight history →	SEA 13:38	LAX 16:25	55%	10%	0.7%	82%worse than usual
F9 1178 Frontier Flight history →	SEA 20:30	LAX 23:19	55%	20%	1.0%	83%worse than usual
AS 1390 Alaska Flight history →	SEA 17:10	LAX 19:49	58%	10%	0.6%	72%worse than usual
AS 1300 Alaska Flight history →	SEA 15:59	LAX 18:44	58%	9%	0.6%	77%worse than usual
AS 487 Alaska Flight history →	SEA 11:15	LAX 14:01	67%	11%	0.8%	57%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 Sun, Oct 4 (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