Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 15 nonstops

Fri, Oct 9: DL 3750 at 07:15 is the safest bet, 7% chance of being 15+ min late; evening flights run 14–26%.

Safest bet that day DL 3750 SEA 07:15 → BOI 09:53 · 7% chance 15+ min late · usually 93% on time Riskiest AS 463 SEA 21:31 → BOI 00:04 · 26% chance 15+ min late · usually 65% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


DL 3750 Delta flown by SkyWest Flight history →	SEA 07:15	BOI 09:53	7%	3%	0.6%	93%
AS 248 Alaska Flight history →	SEA 07:07	BOI 09:40	10%	3%	0.6%	90%
DL 3678 Delta flown by SkyWest Flight history →	SEA 09:00	BOI 11:38	11%	4%	0.6%	91%
DL 3959 Delta flown by SkyWest Flight history →	SEA 12:30	BOI 15:11	12%	5%	0.5%	88%
DL 3688 Delta flown by SkyWest Flight history →	SEA 16:10	BOI 18:46	14%	6%	0.5%	86%
DL 4127 Delta flown by SkyWest Flight history →	SEA 14:50	BOI 17:24	15%	6%	0.5%	88%
DL 3692 Delta flown by SkyWest Flight history →	SEA 19:40	BOI 22:18	16%	6%	0.6%	87%
DL 4090 Delta flown by SkyWest Flight history →	SEA 21:20	BOI 23:51	17%	5%	0.6%	85%
AS 441 Alaska Flight history →	SEA 12:55	BOI 15:26	22%	4%	0.6%	83%
AS 463 Alaska Flight history →	SEA 21:31	BOI 00:04	26%	6%	0.6%	65%
AS 2061 Alaska flown by Horizon no forecast: 12-month record	SEA 15:45	BOI 18:11	10%	4%	0.0%	90%
AS 2034 Alaska flown by Horizon no forecast: 12-month record	SEA 19:59	BOI 22:24	14%	8%	0.0%	86%
AS 2109 Alaska flown by Horizon no forecast: 12-month record	SEA 17:40	BOI 20:07	18%	2%	0.7%	82%
AS 2230 Alaska flown by Horizon no forecast: 12-month record	SEA 09:59	BOI 12:26	19%	5%	0.0%	81%
AS 2106 Alaska flown by Horizon no forecast: 12-month record	SEA 11:36	BOI 14:07	29%	4%	1.8%	71%

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