Today: AA 516 at 06:35 is the safest bet, 10% chance of being 15+ min late; evening flights run 16–30%.

Safest bet today AA 516 DEN 06:35 → PHL 12:19 · 10% chance 15+ min late · usually 91% on time Riskiest WN 1923 DEN 13:30 → PHL 19:06 · 40% chance 15+ min late

Against a calm day 25% average chance a nonstop arrives 15+ min late; 24% 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.


AA 516 American Flight history →	DEN 06:35	PHL 12:19	10%	3%	0.4%	91%
UA 1575 United Flight history →	DEN 09:35	PHL 15:12	13%	6%	0.2%	88%
AA 2344 American Flight history →	DEN 08:41	PHL 14:20	13%	4%	0.4%	84%
AA 2500 American Flight history →	DEN 23:55	PHL 05:32	16%	5%	1.9%	78%
F9 2514 Frontier Flight history →	DEN 06:05	PHL 11:49	17%	6%	1.2%	92%
UA 2787 United	DEN 13:57	PHL 19:43	24%	8%	0.2%	no record
F9 3340 Frontier Flight history →	DEN 23:59	PHL 05:39	24%	14%	1.0%	62%
AA 814 American	DEN 14:51	PHL 20:32	26%	10%	0.3%	no record
AA 1759 American Flight history →	DEN 15:13	PHL 20:59	26%	10%	0.3%	58%
AA 1751 American Flight history →	DEN 12:49	PHL 18:35	27%	8%	0.3%	66%
WN 3157 Southwest Flight history →	DEN 10:30	PHL 16:05	28%	5%	0.2%	72%
AA 2282 American	DEN 12:17	PHL 18:00	28%	8%	0.3%	no record
WN 2686 Southwest Flight history →	DEN 19:05	PHL 00:45	28%	7%	0.5%	22%
WN 1792 Southwest	DEN 19:35	PHL 01:12	28%	8%	0.5%	no record
UA 1510 United Flight history →	DEN 17:54	PHL 23:30	30%	6%	0.7%	58%
WN 1723 Southwest	DEN 11:00	PHL 16:36	32%	5%	0.2%	no record
WN 3286 Southwest Flight history →	DEN 14:05	PHL 19:45	37%	9%	0.2%	67%
WN 1923 Southwest	DEN 13:30	PHL 19:06	40%	7%	0.2%	no record

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