Today: WN 1968 at 13:55 is the safest bet, 29% chance of being 15+ min late; evening flights run 31%.

Safest bet today WN 1968 HOU 13:55 → DCA 18:00 · 29% chance 15+ min late · usually 67% on time Riskiest WN 2031 HOU 14:23 → DCA 18:25 · 39% chance 15+ min late

Against a calm day 33% 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. 2 flights that already left today are not shown.


WN 1968 Southwest Flight history →	HOU 13:55	DCA 18:00	29%	9%	0.5%	67%
WN 3443 Southwest	HOU 19:51	DCA 23:53	31%	10%	0.2%	no record
WN 4888 Southwest Flight history →	HOU 19:55	DCA 23:55	31%	11%	0.2%	48%
WN 2031 Southwest	HOU 14:23	DCA 18:25	39%	10%	0.5%	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