Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 3 nonstops

Fri, Oct 9: WN 1271 at 09:50 is the safest bet, 10% chance of being 15+ min late; evening flights run 33%.

Safest bet that day WN 1271 DAL 09:50 → BHM 11:30 · 10% chance 15+ min late · usually 84% on time Riskiest WN 4389 DAL 16:25 → BHM 18:05 · 33% chance 15+ min late · usually 38% 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.


WN 1271 Southwest Flight history →	DAL 09:50	BHM 11:30	10%	2%	0.6%	84%
WN 4390 Southwest Flight history →	DAL 20:15	BHM 22:00	33%	8%	0.6%	49%
WN 4389 Southwest Flight history →	DAL 16:25	BHM 18:05	33%	7%	0.6%	38%

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