Today: DL 5704 at 21:48 is the safest bet, 16% chance of being 15+ min late; the others run 28–55%.

Safest bet today DL 5704 BOS 21:48 → DCA 23:44 · 16% chance 15+ min late · usually 77% on time Riskiest B6 1955 BOS 17:21 → DCA 19:09 · 55% chance 15+ min late · usually 57% on time

Against a calm day 40% average chance a nonstop arrives 15+ min late; 35% for the same flights on a calm-weather day

Every nonstop today

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. 28 flights that already left today are not shown.


DL 5704 Delta flown by Republic Flight history →	BOS 21:48	DCA 23:44	16%	5%	0.5%	77%
DL 5667 Delta flown by Republic Flight history →	BOS 17:50	DCA 19:56	28%	8%	0.4%	63%
AA 4047 American flown by Envoy Flight history →	BOS 20:22	DCA 22:19	32%	8%	0.9%	55%
DL 5666 Delta flown by Republic Flight history →	BOS 20:05	DCA 22:03	33%	8%	0.5%	59%
AA 1004 American Flight history →	BOS 20:02	DCA 21:55	43%	11%	0.6%	58%
AA 955 American	BOS 17:33	DCA 19:25	46%	11%	0.6%	no record
AA 1557 American Flight history →	BOS 17:23	DCA 19:14	46%	12%	0.7%	53%
B6 2255 JetBlue Flight history →	BOS 18:07	DCA 20:06	48%	19%	0.6%	61%
AA 852 American Flight history →	BOS 19:27	DCA 21:15	48%	14%	0.7%	38%
B6 1955 JetBlue Flight history →	BOS 17:21	DCA 19:09	55%	20%	0.7%	57%worse than usual

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