Monday, October 5 · our forecast odds · issued Sun 3:00 PM ET · 7 nonstops

Tomorrow: WN 863 at 05:55 is the safest bet, 4% chance of being 15+ min late; the others run 9–27%.

Safest bet that day WN 863 STL 05:55 → BOS 09:39 · 4% chance 15+ min late Riskiest WN 3892 STL 14:30 → BOS 18:05 · 27% chance 15+ min late · usually 38% on time

Against a calm day 15% average chance a nonstop arrives 15+ min late; 11% 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 863 Southwest	STL 05:55	BOS 09:39	4%	1%	0.5%	no record
AA 3814 American flown by Envoy Flight history →	STL 09:39	BOS 13:24	9%	3%	0.6%	90%
WN 3891 Southwest Flight history →	STL 09:55	BOS 13:30	12%	3%	0.5%	82%
MQ 3546 Envoy	STL 10:01	BOS 13:42	12%	4%	0.6%	no record
WN 485 Southwest	STL 10:20	BOS 13:56	13%	3%	0.5%	no record
WN 4724 Southwest Flight history →	STL 19:55	BOS 23:30	26%	5%	0.5%	61%
WN 3892 Southwest Flight history →	STL 14:30	BOS 18:05	27%	6%	0.5%	38%

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