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: DL 5813 at 06:21 is the safest bet, 3% chance of being 15+ min late; evening flights run 15–38%.

Safest bet that day DL 5813 BWI 06:21 → BOS 08:00 · 3% chance 15+ min late · usually 97% on time Riskiest WN 4361 BWI 20:05 → BOS 21:40 · 38% chance 15+ min late · usually 38% 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.


DL 5813 Delta flown by Republic Flight history →	BWI 06:21	BOS 08:00	3%	2%	0.7%	97%
WN 883 Southwest Flight history →	BWI 06:40	BOS 08:10	4%	1%	0.7%	92%
DL 5703 Delta flown by Republic Flight history →	BWI 09:00	BOS 10:38	5%	2%	0.7%	91%
WN 884 Southwest Flight history →	BWI 08:15	BOS 09:50	6%	1%	0.7%	89%
WN 887 Southwest Flight history →	BWI 10:40	BOS 12:10	9%	2%	0.7%	80%
DL 5668 Delta flown by Republic Flight history →	BWI 13:45	BOS 15:23	12%	4%	0.7%	80%
DL 5644 Delta flown by Republic Flight history →	BWI 18:22	BOS 20:07	15%	6%	0.7%	67%
WN 211 Southwest Flight history →	BWI 13:40	BOS 15:15	23%	5%	0.7%	68%
WN 892 Southwest Flight history →	BWI 22:30	BOS 00:10	26%	6%	0.7%	56%
WN 737 Southwest Flight history →	BWI 15:35	BOS 17:10	29%	7%	0.7%	54%
WN 4361 Southwest Flight history →	BWI 20:05	BOS 21:40	38%	9%	0.7%	38%

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