Today looks rough: weather pushes the average chance of arriving 15+ min late to 42%, against 29% on a calm day. Safest: AS 439 at 14:38, 39%.

Safest bet today AS 439 IAH 14:38 → SEA 17:21 · 39% chance 15+ min late · usually 72% on time Riskiest UA 692 IAH 18:30 → SEA 21:18 · 47% chance 15+ min late · usually 72% on time

Weather 42% average chance a nonstop arrives 15+ min late; 29% 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. 5 flights that already left today are not shown.


AS 439 Alaska Flight history →	IAH 14:38	SEA 17:21	39%	11%	0.4%	72%worse than usual
UA 2456 United Flight history →	IAH 19:55	SEA 22:42	40%	14%	0.2%	73%worse than usual
UA 2341 United	IAH 20:16	SEA 23:10	40%	15%	0.2%	no record
UA 2638 United Flight history →	IAH 16:25	SEA 19:12	44%	16%	0.2%	67%worse than usual
UA 692 United Flight history →	IAH 18:30	SEA 21:18	47%	14%	0.2%	72%worse than usual

Alternatives with one stop that day

All connections →


Delta Details →	IAH 19:01 → SLC 21:15DL 1299	1h 30m Salt Lake City	SLC 22:45 → SEA 23:59DL 2998	6h 58m	83%	57%

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