Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 11 nonstops

Fri, Oct 9: AS 1505 at 06:03 is the safest bet, 11% chance of being 15+ min late; evening flights run 23–41%.

Safest bet that day AS 1505 SEA 06:03 → BOS 14:23 · 11% chance 15+ min late · usually 100% on time Riskiest B6 398 SEA 11:45 → BOS 20:13 · 41% chance 15+ min late · usually 55% on time

Every nonstop on Fri, Oct 9

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.


AS 1505 Alaska Flight history →	SEA 06:03	BOS 14:23	11%	3%	0.7%	100%worse than usual
DL 459 Delta Flight history →	SEA 07:29	BOS 16:00	12%	4%	0.7%	88%
AS 306 Alaska Flight history →	SEA 08:23	BOS 16:53	23%	5%	0.7%	76%
DL 474 Delta Flight history →	SEA 16:00	BOS 00:14	23%	7%	0.7%	71%
DL 473 Delta Flight history →	SEA 23:15	BOS 07:35	24%	4%	0.7%	82%
DL 438 Delta Flight history →	SEA 11:15	BOS 19:43	25%	8%	0.7%	65%
AS 460 Alaska Flight history →	SEA 15:36	BOS 23:59	29%	6%	0.7%	80%
AS 536 Alaska Flight history →	SEA 23:18	BOS 07:40	29%	4%	0.7%	78%
AS 219 Alaska Flight history →	SEA 10:13	BOS 18:41	36%	8%	0.7%	58%
B6 198 JetBlue Flight history →	SEA 23:44	BOS 08:02	41%	13%	0.8%	53%
B6 398 JetBlue Flight history →	SEA 11:45	BOS 20:13	41%	16%	0.7%	55%

Alternatives with one stop that day

All connections →


Delta Details →	SEA 06:05 → MSP 11:24DL 943	1h 26m Minneapolis	MSP 12:50 → BOS 16:50DL 2558	7h 45m	96%	79%
Delta Details →	SEA 05:30 → DTW 12:42DL 812	1h 19m Detroit	DTW 14:01 → BOS 16:09DL 1171	7h 39m	97%	78%
United Details →	SEA 05:00 → DEN 08:43UA 2601	57m Denver	DEN 09:40 → BOS 15:44UA 1232	7h 44m	93%	78%

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 Fri, Oct 9 (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