Today: WN 1424 at 05:10 is the safest bet, 5% chance of being 15+ min late; evening flights run 18–38%.

Safest bet today WN 1424 SFO 05:10 → DEN 08:40 · 5% chance 15+ min late · usually 96% on time Riskiest F9 1094 SFO 12:04 → DEN 15:46 · 45% chance 15+ min late · usually 43% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 21% 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.


WN 1424 Southwest Flight history →	SFO 05:10	DEN 08:40	5%	1%	0.1%	96%
WN 3774 Southwest	SFO 06:00	DEN 09:32	5%	1%	0.1%	no record
UA 1479 United Flight history →	SFO 05:00	DEN 08:35	5%	1%	0.1%	96%
UA 1758 United Flight history →	SFO 06:15	DEN 09:59	7%	1%	0.2%	81%
UA 2448 United	SFO 06:09	DEN 09:45	8%	1%	0.2%	no record
UA 2348 United Flight history →	SFO 08:31	DEN 12:22	13%	3%	0.2%	84%
UA 1469 United	SFO 08:52	DEN 12:44	13%	4%	0.2%	no record
F9 1230 Frontier Flight history →	SFO 06:00	DEN 09:46	15%	4%	0.8%	88%
UA 301 United Flight history →	SFO 21:00	DEN 00:47	18%	6%	0.5%	86%
WN 4619 Southwest	SFO 09:35	DEN 13:06	18%	2%	0.1%	no record
UA 2436 United Flight history →	SFO 18:56	DEN 22:44	19%	5%	0.5%	88%
UA 2019 United Flight history →	SFO 19:56	DEN 23:43	19%	5%	0.5%	88%
UA 1214 United Flight history →	SFO 17:30	DEN 21:28	19%	5%	0.5%	81%
UA 2117 United	SFO 19:52	DEN 23:36	20%	5%	0.5%	no record
UA 540 United Flight history →	SFO 12:43	DEN 16:35	24%	4%	0.2%	77%
UA 1430 United Flight history →	SFO 16:10	DEN 20:01	24%	5%	0.5%	79%
UA 1604 United Flight history →	SFO 10:40	DEN 14:23	26%	5%	0.2%	68%
UA 1596 United Flight history →	SFO 14:20	DEN 18:11	28%	5%	0.2%	71%
UA 1835 United	SFO 16:19	DEN 19:52	31%	6%	0.5%	no record
WN 3776 Southwest	SFO 11:45	DEN 15:16	33%	5%	0.1%	no record
WN 3642 Southwest Flight history →	SFO 19:20	DEN 23:00	33%	7%	0.5%	50%
WN 4284 Southwest Flight history →	SFO 10:00	DEN 13:30	37%	4%	0.1%	12%
WN 3641 Southwest Flight history →	SFO 14:35	DEN 18:10	38%	6%	0.5%	10%
F9 3440 Frontier Flight history →	SFO 16:30	DEN 20:15	38%	9%	0.7%	61%
WN 137 Southwest	SFO 14:15	DEN 17:46	39%	7%	0.1%	no record
F9 1094 Frontier Flight history →	SFO 12:04	DEN 15:46	45%	12%	0.7%	43%

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