Today: UA 1869 at 10:59 is the safest bet, 12% chance of being 15+ min late; evening flights run 21–31%.

Safest bet today UA 1869 ORD 10:59 → IAD 14:04 · 12% chance 15+ min late · usually 89% on time Riskiest UA 2202 ORD 18:09 → IAD 21:18 · 31% chance 15+ min late · usually 57% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 26% 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. 2 flights that already left today are not shown.


UA 1869 United Flight history →	ORD 10:59	IAD 14:04	12%	6%	0.2%	89%
UA 1486 United	ORD 10:51	IAD 13:45	18%	9%	0.2%	no record
UA 1128 United	ORD 12:51	IAD 15:46	20%	6%	0.2%	no record
UA 2766 United Flight history →	ORD 21:40	IAD 00:45	21%	6%	0.2%	69%
UA 587 United Flight history →	ORD 14:57	IAD 18:00	22%	7%	0.2%	73%
UA 304 United	ORD 20:11	IAD 23:09	24%	6%	0.2%	no record
UA 1922 United	ORD 21:42	IAD 00:35	25%	6%	0.2%	no record
UA 2794 United Flight history →	ORD 13:30	IAD 16:30	28%	7%	0.2%	76%
UA 2202 United Flight history →	ORD 18:09	IAD 21:18	31%	7%	0.2%	57%

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 Sun, Oct 4 (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