Today looks rough: weather pushes the average chance of arriving 15+ min late to 48%, against 34% on a calm day. Safest: UA 2428 at 11:44, 38%.

Safest bet today UA 2428 SAN 11:44 → SFO 13:30 · 38% chance 15+ min late · usually 72% on time Riskiest F9 3383 SAN 19:46 → SFO 21:38 · 54% chance 15+ min late · usually 27% on time

Weather 48% average chance a nonstop arrives 15+ min late; 34% 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. 14 flights that already left today are not shown.


UA 2428 United Flight history →	SAN 11:44	SFO 13:30	38%	10%	0.3%	72%worse than usual
UA 1835 United	SAN 12:46	SFO 14:43	42%	14%	0.4%	no record
WN 309 Southwest	SAN 21:55	SFO 23:35	45%	14%	0.3%	no record
WN 2620 Southwest	SAN 12:45	SFO 14:20	45%	10%	0.3%	no record
AS 291 Alaska Flight history →	SAN 21:27	SFO 23:08	45%	12%	0.8%	42%
AS 3482 Alaska flown by SkyWest Flight history →	SAN 16:03	SFO 17:44	46%	17%	0.5%	76%worse than usual
UA 2117 United Flight history →	SAN 16:09	SFO 17:49	46%	18%	0.3%	76%worse than usual
AS 3352 Alaska flown by SkyWest Flight history →	SAN 13:24	SFO 15:08	46%	12%	0.5%	74%worse than usual
UA 2278 United Flight history →	SAN 19:41	SFO 21:28	47%	18%	0.2%	37%
WN 3480 Southwest	SAN 20:13	SFO 21:49	47%	13%	0.3%	no record
WN 3581 Southwest	SAN 16:46	SFO 18:22	48%	13%	0.4%	no record
UA 1763 United Flight history →	SAN 13:39	SFO 15:19	48%	14%	0.3%	74%worse than usual
AS 3463 Alaska flown by SkyWest Flight history →	SAN 19:58	SFO 21:39	48%	15%	0.6%	63%worse than usual
AS 3232 Alaska flown by SkyWest Flight history →	SAN 18:31	SFO 20:12	48%	16%	0.7%	28%
WN 1193 Southwest	SAN 14:41	SFO 16:18	49%	14%	0.3%	no record
UA 1302 United Flight history →	SAN 18:27	SFO 20:07	49%	19%	0.2%	62%worse than usual
WN 3228 Southwest	SAN 21:26	SFO 23:02	49%	14%	0.3%	no record
AS 1331 Alaska	SAN 20:55	SFO 22:30	49%	14%	0.8%	no record
WN 345 Southwest	SAN 16:30	SFO 18:00	50%	14%	0.3%	no record
AS 453 Alaska	SAN 18:51	SFO 20:26	50%	15%	0.9%	no record
WN 1158 Southwest	SAN 20:00	SFO 21:35	52%	15%	0.3%	no record
WN 430 Southwest	SAN 19:18	SFO 20:55	52%	16%	0.3%	no record
F9 3383 Frontier Flight history →	SAN 19:46	SFO 21:38	54%	25%	2.3%	27%
AS 2314 Alaska flown by Horizon no forecast: 12-month record	SAN 16:14	SFO 17:49	72%	10%	3.8%	28%

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