Today: WN 4777 at 08:19 is the safest bet, 9% chance of being 15+ min late; evening flights run 26–33%.

Safest bet today WN 4777 BHM 08:19 → BNA 09:32 · 9% chance 15+ min late Riskiest WN 451 BHM 16:50 → BNA 18:03 · 33% chance 15+ min late

Against a calm day 23% average chance a nonstop arrives 15+ min late; 17% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, 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. 1 flight that already left today is not shown.


WN 4777 Southwest	BHM 08:19	BNA 09:32	9%	2%	0.2%	no record
WN 4389 Southwest Flight history →	BHM 18:40	BNA 19:40	26%	6%	0.6%	19%
WN 451 Southwest	BHM 16:50	BNA 18:03	33%	6%	0.2%	no record

How these are worked out. Each flight’s odds are our forecast for that day; 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 Mon, Oct 5 (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