Monday, October 5 · our forecast odds · issued Sun 9:00 PM ET · 13 nonstops

Tomorrow: WN 3937 at 06:50 is the safest bet, 10% chance of being 15+ min late; evening flights run 15–30%.

Safest bet that day WN 3937 ATL 06:50 → STL 07:30 · 10% chance 15+ min late · usually 96% on time Riskiest WN 4816 ATL 20:15 → STL 21:06 · 30% chance 15+ min late

Against a calm day 18% average chance a nonstop arrives 15+ min late; 16% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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 3937 Southwest Flight history →	ATL 06:50	STL 07:30	10%	1%	0.2%	96%
WN 255 Southwest	ATL 07:03	STL 07:54	10%	2%	0.2%	no record
DL 2700 Delta Flight history →	ATL 14:09	STL 14:48	13%	3%	0.8%	90%
DL 1571 Delta Flight history →	ATL 07:43	STL 08:19	14%	2%	0.7%	92%
DL 1403 Delta Flight history →	ATL 23:10	STL 23:53	15%	5%	0.8%	83%
DL 543 Delta Flight history →	ATL 15:17	STL 16:09	16%	3%	0.7%	81%
DL 566 Delta Flight history →	ATL 11:40	STL 12:17	18%	3%	0.9%	83%
DL 1393 Delta Flight history →	ATL 17:10	STL 17:53	18%	4%	0.7%	79%
DL 1400 Delta Flight history →	ATL 09:04	STL 09:43	18%	3%	0.6%	87%
DL 2833 Delta Flight history →	ATL 19:14	STL 20:06	19%	5%	0.7%	76%
WN 244 Southwest	ATL 13:32	STL 14:23	20%	3%	0.6%	no record
F9 4473 Frontier Flight history →	ATL 12:24	STL 13:26	28%	9%	1.2%	69%
WN 4816 Southwest	ATL 20:15	STL 21:06	30%	6%	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