Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · connections flying that day

Sun, Oct 11: one nonstop, WN 1397 at 17:50, with a 32% chance of arriving 15+ min late.

Nonstops that day

All 1 nonstop →


WN 1397 Southwest	BHM 17:50	MDW 19:56	32%	8%	3.6%	no record

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Chicago on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival. Layovers up to 4 hours. Pick a connection for its 12-month details.


Delta Details →	BHM 05:19 → ATL 07:23DL 2162	3h 37m Atlanta	ATL 11:00 → MDW 11:56DL 2417	6h 37m	100%	86%
Delta Details →	BHM 06:25 → DTW 09:27DL 3006	2h 58m Detroit	DTW 12:25 → MDW 12:46DL 4688 · flown by Endeavor	6h 21m	99%	79%
Delta Details →	BHM 09:30 → ATL 11:34DL 3100	3h 41m Atlanta	ATL 15:15 → MDW 16:15DL 1728	6h 45m	100%	73%
Delta Details →	BHM 16:00 → ATL 18:14DL 3163	3h 01m Atlanta	ATL 21:15 → MDW 22:15DL 1076	6h 15m	96%	69%

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 Sun, Oct 11 (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