Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · 3 nonstops

Sun, Oct 11 looks like a normal day here: all 2 nonstops are 19–22% likely to arrive 15+ min late.

Safest bet that day DL 4104 SEA 12:17 → BZN 15:14 · 19% chance 15+ min late · usually 84% on time Riskiest DL 4039 SEA 19:59 → BZN 22:49 · 22% chance 15+ min late · usually 84% on time

Every nonstop on Sun, Oct 11

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 4104 Delta flown by SkyWest Flight history →	SEA 12:17	BZN 15:14	19%	4%	0.7%	84%
DL 4039 Delta flown by SkyWest Flight history →	SEA 19:59	BZN 22:49	22%	6%	0.8%	84%
AS 2141 Alaska flown by Horizon no forecast: 12-month record	SEA 07:06	BZN 09:46	5%	1%	1.1%	95%

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 Sun, Oct 11 (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