Today looks rough: weather pushes the average chance of arriving 15+ min late to 38%, against 25% on a calm day. Safest: WN 778 at 11:15, 26%.

Safest bet today WN 778 DEN 11:15 → HOU 14:45 · 26% chance 15+ min late Riskiest WN 1600 DEN 20:35 → HOU 00:04 · 55% chance 15+ min late

Weather 38% 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. 3 flights that already left today are not shown.


WN 778 Southwest	DEN 11:15	HOU 14:45	26%	3%	0.4%	no record
WN 1597 Southwest	DEN 11:00	HOU 14:28	26%	3%	0.4%	no record
WN 4525 Southwest	DEN 13:45	HOU 17:13	32%	6%	0.4%	no record
WN 3433 Southwest	DEN 21:55	HOU 01:24	37%	8%	0.6%	no record
WN 1478 Southwest	DEN 16:20	HOU 19:49	37%	11%	0.4%	no record
WN 2026 Southwest Flight history →	DEN 20:55	HOU 00:30	53%	11%	0.2%	54%
WN 1600 Southwest	DEN 20:35	HOU 00:04	55%	11%	0.3%	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