Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 4 nonstops

Thu, Oct 8: WN 643 at 05:24 is the safest bet, 2% chance of being 15+ min late; the others run 3–16%.

Safest bet that day WN 643 BNA 05:24 → MDW 07:12 · 2% chance 15+ min late Riskiest WN 3390 BNA 16:26 → MDW 18:12 · 16% chance 15+ min late

Every nonstop on Thu, Oct 8

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 643 Southwest	BNA 05:24	MDW 07:12	2%	1%	0.6%	no record
WN 644 Southwest	BNA 07:30	MDW 09:18	3%	1%	0.6%	no record
WN 1724 Southwest	BNA 14:27	MDW 16:13	13%	4%	0.6%	no record
WN 3390 Southwest	BNA 16:26	MDW 18:12	16%	5%	0.6%	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 Thu, Oct 8 (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