Today: only flights still to leave (it’s 7:34 pm at San Francisco); 20 already left

Sunday, October 4 · our forecast odds · issued Sun 9:00 PM ET · 6 nonstops

Today: UA 301 at 21:00 is the safest bet, 37% chance of being 15+ min late; the others run 38–55%.

Safest bet today UA 301 SFO 21:00 → DEN 00:47 · 37% chance 15+ min late · usually 86% on time Riskiest WN 3798 SFO 21:42 → DEN 00:35 · 55% chance 15+ min late

Against a calm day 44% average chance a nonstop arrives 15+ min late; 35% 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. 20 flights that already left today are not shown.


UA 301 United Flight history →	SFO 21:00	DEN 00:47	37%	12%	0.1%	86%worse than usual
UA 2019 United Flight history →	SFO 19:56	DEN 23:43	38%	11%	0.1%	88%worse than usual
DL 8848 Delta	SFO 20:47	DEN 00:13	38%	14%	0.7%	no record
F9 3440 Frontier Flight history →	SFO 21:39	DEN 01:29	45%	19%	0.6%	61%
UA 2117 United	SFO 20:07	DEN 23:11	49%	14%	0.1%	no record
WN 3798 Southwest	SFO 21:42	DEN 00:35	55%	11%	0.1%	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 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