Saturday, October 10 · typical odds for a Saturday (too early for a weather forecast) · issued Sun 12:00 AM ET · 4 nonstops

Sat, Oct 10: WN 634 at 08:02 is the safest bet, 6% chance of being 15+ min late; the others run 9–27%.

Safest bet that day WN 634 MDW 08:02 → BOS 11:12 · 6% chance 15+ min late Riskiest WN 4942 MDW 16:24 → BOS 19:54 · 27% chance 15+ min late

Every nonstop on Sat, Oct 10

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 634 Southwest	MDW 08:02	BOS 11:12	6%	1%	0.6%	no record
WN 2842 Southwest	MDW 09:54	BOS 13:24	9%	2%	0.6%	no record
WN 4429 Southwest	MDW 12:26	BOS 15:43	17%	4%	0.6%	no record
WN 4942 Southwest	MDW 16:24	BOS 19:54	27%	7%	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 Sat, Oct 10 (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