Today: UA 1720 at 07:42 is the safest bet, 13% chance of being 15+ min late; evening flights run 24–37%.

Safest bet today UA 1720 DEN 07:42 → IAH 11:15 · 13% chance 15+ min late · usually 92% on time Riskiest F9 2996 DEN 21:06 → IAH 00:40 · 37% chance 15+ min late · usually 76% on time

Against a calm day 24% average chance a nonstop arrives 15+ min late; 25% 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. 1 flight that already left today is not shown.


UA 1720 United Flight history →	DEN 07:42	IAH 11:15	13%	3%	0.1%	92%
UA 1129 United Flight history →	DEN 10:07	IAH 13:40	16%	4%	0.1%	70%
UA 2030 United	DEN 09:56	IAH 13:17	17%	4%	0.1%	no record
UA 1599 United Flight history →	DEN 11:34	IAH 15:09	18%	4%	0.1%	78%
UA 489 United Flight history →	DEN 15:35	IAH 19:10	20%	7%	0.1%	78%
UA 1829 United Flight history →	DEN 13:30	IAH 17:04	21%	6%	0.1%	73%
UA 2791 United Flight history →	DEN 18:05	IAH 21:36	24%	7%	0.2%	56%
UA 1253 United Flight history →	DEN 21:10	IAH 00:41	24%	6%	0.6%	67%
UA 588 United Flight history →	DEN 16:20	IAH 19:57	25%	7%	0.1%	78%
F9 3206 Frontier Flight history →	DEN 07:00	IAH 10:34	25%	5%	0.6%	87%worse than usual
UA 1587 United Flight history →	DEN 17:13	IAH 20:34	28%	8%	0.2%	82%
UA 1055 United	DEN 18:03	IAH 21:25	28%	7%	0.2%	no record
UA 2419 United Flight history →	DEN 20:28	IAH 23:59	28%	6%	0.7%	80%
F9 3228 Frontier Flight history →	DEN 17:35	IAH 21:14	30%	9%	0.5%	76%
UA 475 United Flight history →	DEN 19:35	IAH 23:06	30%	6%	0.7%	75%
F9 2996 Frontier Flight history →	DEN 21:06	IAH 00:40	37%	13%	0.7%	76%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