Monday, October 5 · our forecast odds · issued Sun 8:00 PM ET · 10 nonstops

Tomorrow: WN 1587 at 06:55 is the safest bet, 9% chance of being 15+ min late; evening flights run 28–33%.

Safest bet that day WN 1587 PHL 06:55 → MDW 08:09 · 9% chance 15+ min late Riskiest WN 3363 PHL 19:10 → MDW 20:24 · 33% chance 15+ min late

Against a calm day 22% average chance a nonstop arrives 15+ min late; 20% 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 1587 Southwest	PHL 06:55	MDW 08:09	9%	1%	0.4%	no record
WN 4202 Southwest Flight history →	PHL 08:00	MDW 09:05	16%	2%	0.4%	85%
WN 3224 Southwest Flight history →	PHL 11:20	MDW 12:30	16%	2%	0.6%	88%
WN 3003 Southwest	PHL 11:31	MDW 12:45	18%	2%	0.6%	no record
WN 4837 Southwest Flight history →	PHL 12:50	MDW 13:50	19%	3%	0.6%	69%
WN 4440 Southwest	PHL 13:56	MDW 15:10	25%	3%	0.7%	no record
WN 3433 Southwest	PHL 15:21	MDW 16:35	26%	5%	0.7%	no record
WN 3226 Southwest Flight history →	PHL 18:55	MDW 20:20	28%	6%	0.7%	62%
WN 2756 Southwest Flight history →	PHL 17:20	MDW 18:30	28%	6%	0.6%	48%
WN 3363 Southwest	PHL 19:10	MDW 20:24	33%	6%	0.7%	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