Saturday, October 10 · typical odds for a Saturday (too early for a weather forecast) · issued Sun 12:00 AM ET · 6 nonstops

Sat, Oct 10: DL 3816 at 06:20 is the safest bet, 8% chance of being 15+ min late; evening flights run 17–22%.

Safest bet that day DL 3816 ONT 06:20 → SEA 09:15 · 8% chance 15+ min late · usually 94% on time Riskiest AS 1679 ONT 14:21 → SEA 16:52 · 26% chance 15+ min late

Every nonstop on Sat, Oct 10

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.


DL 3816 Delta flown by SkyWest Flight history →	ONT 06:20	SEA 09:15	8%	3%	0.8%	94%
AS 607 Alaska Flight history →	ONT 06:02	SEA 08:44	10%	2%	2.1%	93%
DL 4031 Delta flown by SkyWest Flight history →	ONT 18:01	SEA 20:50	17%	6%	0.8%	90%
AS 1671 Alaska	ONT 11:21	SEA 13:54	17%	3%	1.4%	no record
F9 2275 Frontier Flight history →	ONT 18:00	SEA 20:52	22%	7%	1.0%	80%
AS 1679 Alaska	ONT 14:21	SEA 16:52	26%	4%	1.2%	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 Sat, Oct 10 (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