Monday, October 5 · our forecast odds · issued Sun 6:00 PM ET · 12 nonstops

Tomorrow: DL 459 at 07:29 is the safest bet, 13% chance of being 15+ min late; evening flights run 19–41%.

Safest bet that day DL 459 SEA 07:29 → BOS 16:00 · 13% chance 15+ min late · usually 88% on time Riskiest B6 198 SEA 23:46 → BOS 08:04 · 41% chance 15+ min late · usually 53% on time

Against a calm day 24% average chance a nonstop arrives 15+ min late; 24% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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 459 Delta Flight history →	SEA 07:29	BOS 16:00	13%	3%	0.7%	88%
AS 1505 Alaska Flight history →	SEA 06:03	BOS 14:23	16%	3%	0.7%	100%worse than usual
DL 473 Delta Flight history →	SEA 23:15	BOS 07:35	19%	5%	0.6%	82%
DL 474 Delta Flight history →	SEA 16:00	BOS 00:14	19%	6%	0.6%	71%
DL 438 Delta Flight history →	SEA 11:15	BOS 19:43	19%	6%	0.6%	65%
AS 306 Alaska Flight history →	SEA 08:23	BOS 16:53	21%	5%	0.7%	76%
AS 288 Alaska	SEA 07:16	BOS 15:27	21%	5%	0.7%	no record
AS 536 Alaska Flight history →	SEA 23:18	BOS 07:40	22%	5%	0.6%	78%
AS 460 Alaska Flight history →	SEA 15:36	BOS 23:59	25%	6%	0.6%	80%
AS 219 Alaska Flight history →	SEA 10:13	BOS 18:41	33%	8%	0.7%	58%
B6 398 JetBlue Flight history →	SEA 11:45	BOS 20:13	39%	16%	0.7%	55%
B6 198 JetBlue Flight history →	SEA 23:46	BOS 08:04	41%	14%	0.7%	53%

Alternatives with one stop that day

All connections →


Delta Details →	SEA 00:19 → MSP 05:38DL 953	1h 22m Minneapolis	MSP 07:00 → BOS 10:45DL 2649	7h 26m	94%	87%
Southwest Details →	SEA 05:30 → MDW 11:25WN 2810	1h 05m Chicago	MDW 12:30 → BOS 15:50WN 4716	7h 20m	100%	80%
Delta Details →	SEA 06:05 → MSP 11:24DL 943	1h 26m Minneapolis	MSP 12:50 → BOS 16:50DL 2558	7h 45m	95%	79%

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