Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 5 nonstops

Thu, Oct 8: WN 4305 at 05:51 is the safest bet, 4% chance of being 15+ min late; evening flights run 30–37%.

Safest bet that day WN 4305 BOS 05:51 → MDW 07:26 · 4% chance 15+ min late Riskiest WN 4233 BOS 18:36 → MDW 20:16 · 37% 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 4305 Southwest	BOS 05:51	MDW 07:26	4%	1%	0.8%	no record
WN 1955 Southwest	BOS 07:06	MDW 08:41	9%	2%	0.8%	no record
WN 807 Southwest	BOS 13:11	MDW 14:49	19%	5%	0.7%	no record
WN 2799 Southwest	BOS 16:51	MDW 18:30	30%	9%	0.7%	no record
WN 4233 Southwest	BOS 18:36	MDW 20:16	37%	11%	0.7%	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