Today: WN 1845 at 08:14 is the safest bet, 7% chance of being 15+ min late; evening flights run 25–30%.

Safest bet today WN 1845 DTW 08:14 → MDW 08:35 · 7% chance 15+ min late Riskiest WN 1782 DTW 20:30 → MDW 20:40 · 30% chance 15+ min late · usually 39% on time

Against a calm day 18% average chance a nonstop arrives 15+ min late; 18% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


WN 1845 Southwest	DTW 08:14	MDW 08:35	7%	1%	0.1%	no record
WN 1781 Southwest Flight history →	DTW 08:40	MDW 08:55	9%	2%	0.2%	86%
WN 4477 Southwest	DTW 14:45	MDW 15:06	16%	3%	0.1%	no record
WN 507 Southwest Flight history →	DTW 13:25	MDW 13:35	21%	4%	0.2%	31%
WN 1849 Southwest	DTW 20:05	MDW 20:26	25%	4%	0.5%	no record
WN 1782 Southwest Flight history →	DTW 20:30	MDW 20:40	30%	5%	0.5%	39%
DL 4688 Delta flown by Endeavor no forecast: 12-month record	DTW 12:25	MDW 12:46	18%	8%	1.2%	82%
DL 4684 Delta flown by Endeavor no forecast: 12-month record	DTW 08:50	MDW 09:14	26%	3%	0.0%	74%
DL 4677 Delta flown by Endeavor no forecast: 12-month record	DTW 18:07	MDW 18:25	40%	24%	1.2%	60%

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