Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 7 nonstops

Fri, Oct 9: WN 1598 at 05:55 is the safest bet, 3% chance of being 15+ min late; evening flights run 24–30%.

Safest bet that day WN 1598 DEN 05:55 → MDW 09:20 · 3% chance 15+ min late · usually 98% on time Riskiest WN 1604 DEN 17:35 → MDW 21:00 · 30% chance 15+ min late · usually 27% 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 1598 Southwest Flight history →	DEN 05:55	MDW 09:20	3%	1%	0.7%	98%
WN 114 Southwest Flight history →	DEN 07:10	MDW 10:30	5%	1%	0.6%	94%
WN 755 Southwest Flight history →	DEN 10:00	MDW 13:25	11%	2%	0.6%	89%
WN 1601 Southwest Flight history →	DEN 13:00	MDW 16:20	20%	5%	0.6%	59%
WN 1603 Southwest Flight history →	DEN 15:50	MDW 19:15	23%	7%	0.6%	61%
WN 1615 Southwest Flight history →	DEN 20:50	MDW 00:15	24%	7%	0.7%	36%
WN 1604 Southwest Flight history →	DEN 17:35	MDW 21:00	30%	8%	0.6%	27%

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