Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 20 nonstops

Fri, Oct 9: DL 4008 at 05:30 is the safest bet, 7% chance of being 15+ min late; evening flights run 18–29%.

Safest bet that day DL 4008 PDX 05:30 → SEA 06:35 · 7% chance 15+ min late · usually 95% on time Riskiest AS 427 PDX 09:19 → SEA 10:21 · 40% chance 15+ min late · usually 48% 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 4008 Delta flown by SkyWest Flight history →	PDX 05:30	SEA 06:35	7%	2%	0.6%	95%
AS 499 Alaska Flight history →	PDX 06:19	SEA 07:17	7%	1%	0.8%	93%
DL 4471 Delta flown by SkyWest Flight history →	PDX 07:05	SEA 08:15	13%	3%	0.6%	93%
DL 3802 Delta flown by SkyWest Flight history →	PDX 12:23	SEA 13:34	15%	5%	0.6%	87%
DL 3818 Delta flown by SkyWest Flight history →	PDX 11:15	SEA 12:30	15%	4%	0.6%	91%
AS 3431 Alaska flown by SkyWest Flight history →	PDX 10:35	SEA 11:43	16%	4%	0.6%	81%
AS 3078 Alaska flown by SkyWest Flight history →	PDX 12:03	SEA 13:03	17%	5%	0.6%	86%
DL 3918 Delta flown by SkyWest Flight history →	PDX 17:50	SEA 18:59	18%	5%	0.6%	86%
DL 4062 Delta flown by SkyWest Flight history →	PDX 15:30	SEA 16:38	21%	5%	0.6%	89%worse than usual
DL 3953 Delta flown by SkyWest Flight history →	PDX 09:32	SEA 10:55	23%	4%	0.6%	85%
AS 3408 Alaska flown by SkyWest Flight history →	PDX 15:30	SEA 16:30	25%	5%	0.6%	81%
DL 3923 Delta flown by SkyWest Flight history →	PDX 20:44	SEA 21:56	27%	6%	0.7%	79%
AS 430 Alaska Flight history →	PDX 17:30	SEA 18:33	29%	5%	0.7%	77%
AS 427 Alaska Flight history →	PDX 09:19	SEA 10:21	40%	5%	0.8%	48%
AS 2420 Alaska flown by Horizon no forecast: 12-month record	PDX 07:19	SEA 08:20	2%	0%	1.9%	98%
AS 2431 Alaska flown by Horizon no forecast: 12-month record	PDX 05:00	SEA 05:53	6%	4%	1.9%	94%
AS 2108 Alaska flown by Horizon no forecast: 12-month record	PDX 08:19	SEA 09:14	8%	4%	1.9%	92%
AS 2421 Alaska flown by Horizon no forecast: 12-month record	PDX 21:30	SEA 22:27	10%	6%	0.0%	90%
AS 2205 Alaska flown by Horizon no forecast: 12-month record	PDX 13:48	SEA 14:43	29%	0%	0.0%	71%
AS 2313 Alaska flown by Horizon no forecast: 12-month record	PDX 19:38	SEA 20:33	45%	13%	0.0%	55%

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