Today: YX 4739 at 21:04 is the safest bet, 8% chance of being 15+ min late; morning flights run 11–13%.

Safest bet today YX 4739 ORD 21:04 → TYS 23:53 · 8% chance 15+ min late Riskiest UA 795 ORD 17:58 → TYS 20:36 · 23% chance 15+ min late

Against a calm day 16% average chance a nonstop arrives 15+ min late; 13% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


YX 4739 Republic	ORD 21:04	TYS 23:53	8%	2%	0.6%	no record
UA 2035 United	ORD 06:54	TYS 09:32	11%	2%	0.2%	no record
MQ 4229 Envoy	ORD 08:14	TYS 10:53	13%	2%	0.2%	no record
MQ 3547 Envoy	ORD 15:30	TYS 18:08	13%	4%	0.3%	no record
MQ 3501 Envoy	ORD 13:42	TYS 16:27	15%	3%	0.3%	no record
AA 3783 American flown by Envoy Flight history →	ORD 15:13	TYS 18:02	15%	4%	0.3%	52%
AA 5001 American flown by SkyWest Flight history →	ORD 19:09	TYS 21:58	18%	8%	0.6%	67%
UA 5823 United flown by SkyWest Flight history →	ORD 14:00	TYS 17:00	20%	8%	0.2%	71%
UA 6037 United flown by SkyWest Flight history →	ORD 10:30	TYS 13:19	21%	6%	0.2%	76%
OO 5719 SkyWest	ORD 14:11	TYS 16:51	23%	7%	0.2%	no record
UA 795 United	ORD 17:58	TYS 20:36	23%	9%	0.6%	no record
UA 4551 United flown by GoJet no forecast: 12-month record	ORD 06:55	TYS 09:43	17%	3%	0.0%	83%

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