Today: WN 2131 at 07:45 is the safest bet, 4% chance of being 15+ min late; evening flights run 17–18%.

Safest bet today WN 2131 MDW 07:45 → CLE 10:09 · 4% chance 15+ min late Riskiest WN 4697 MDW 18:45 → CLE 21:09 · 18% chance 15+ min late

Against a calm day 11% average chance a nonstop arrives 15+ min late; 12% 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.


WN 2131 Southwest	MDW 07:45	CLE 10:09	4%	1%	0.2%	no record
WN 4088 Southwest Flight history →	MDW 07:55	CLE 10:10	4%	1%	0.2%	93%
WN 1813 Southwest Flight history →	MDW 12:15	CLE 14:25	9%	1%	0.2%	85%
WN 3220 Southwest	MDW 14:35	CLE 16:59	11%	2%	0.2%	no record
WN 4153 Southwest Flight history →	MDW 19:35	CLE 21:55	17%	4%	0.6%	67%
WN 4697 Southwest	MDW 18:45	CLE 21:09	18%	4%	0.6%	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