Monday, October 12 · typical odds for a Monday (too early for a weather forecast) · issued Tue 12:00 AM ET · 14 nonstops

Mon, Oct 12: WN 3451 at 07:14 is the safest bet, 9% chance of being 15+ min late; evening flights run 13–34%.

Safest bet that day WN 3451 SEA 07:14 → SJC 09:30 · 9% chance 15+ min late Riskiest WN 1554 SEA 21:44 → SJC 23:56 · 34% chance 15+ min late

Every nonstop on Mon, Oct 12

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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.


WN 3451 Southwest	SEA 07:14	SJC 09:30	9%	3%	0.6%	no record
DL 3736 Delta flown by SkyWest Flight history →	SEA 10:07	SJC 12:25	11%	4%	0.6%	91%
DL 4100 Delta flown by SkyWest Flight history →	SEA 17:50	SJC 20:14	13%	4%	0.6%	87%
DL 3956 Delta flown by SkyWest Flight history →	SEA 20:57	SJC 23:16	13%	4%	0.6%	79%
DL 3789 Delta flown by SkyWest Flight history →	SEA 11:45	SJC 14:15	13%	4%	0.6%	84%
DL 3897 Delta flown by SkyWest Flight history →	SEA 15:18	SJC 17:27	17%	4%	0.6%	85%
AS 1341 Alaska Flight history →	SEA 07:34	SJC 09:31	19%	4%	0.8%	92%worse than usual
AS 521 Alaska Flight history →	SEA 14:04	SJC 16:07	27%	4%	0.8%	87%worse than usual
AS 403 Alaska	SEA 20:46	SJC 22:54	27%	6%	0.7%	no record
AS 1303 Alaska Flight history →	SEA 18:07	SJC 20:14	28%	6%	0.7%	83%worse than usual
AS 657 Alaska Flight history →	SEA 15:47	SJC 17:58	29%	5%	0.8%	77%
AS 658 Alaska	SEA 11:26	SJC 13:36	30%	4%	0.8%	no record
WN 3766 Southwest	SEA 13:18	SJC 15:25	30%	5%	0.6%	no record
WN 1554 Southwest	SEA 21:44	SJC 23:56	34%	8%	0.6%	no record

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 12 (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