Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sat 8:00 PM ET · 11 nonstops

Fri, Oct 9: WN 727 at 05:45 is the safest bet, 3% chance of being 15+ min late; evening flights run 13–31%.

Safest bet that day WN 727 BOS 05:45 → BWI 07:20 · 3% chance 15+ min late · usually 89% on time Riskiest WN 735 BOS 19:50 → BWI 21:35 · 31% chance 15+ min late · usually 36% on time

Every nonstop on Fri, Oct 9

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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 727 Southwest Flight history →	BOS 05:45	BWI 07:20	3%	1%	0.6%	89%
DL 5703 Delta flown by Republic Flight history →	BOS 06:35	BWI 08:20	4%	2%	0.7%	90%
DL 5668 Delta flown by Republic Flight history →	BOS 11:10	BWI 12:53	6%	2%	0.7%	84%
WN 732 Southwest Flight history →	BOS 08:55	BWI 10:35	7%	2%	0.6%	92%
DL 5644 Delta flown by Republic Flight history →	BOS 15:50	BWI 17:42	9%	4%	0.7%	79%
DL 5851 Delta flown by Republic Flight history →	BOS 20:35	BWI 22:29	13%	6%	0.8%	63%
WN 733 Southwest Flight history →	BOS 13:25	BWI 15:05	14%	4%	0.6%	91%
WN 1053 Southwest Flight history →	BOS 15:55	BWI 17:40	20%	6%	0.6%	50%
WN 736 Southwest Flight history →	BOS 22:15	BWI 23:55	24%	9%	0.6%	55%
WN 1898 Southwest Flight history →	BOS 17:20	BWI 19:10	26%	9%	0.6%	52%
WN 735 Southwest Flight history →	BOS 19:50	BWI 21:35	31%	9%	0.6%	36%

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 Fri, Oct 9 (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