Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 3 nonstops

Thu, Oct 8: UA 683 at 09:00 is the safest bet, 7% chance of being 15+ min late; the others run 15–18%.

Safest bet that day UA 683 IAD 09:00 → TPA 11:32 · 7% chance 15+ min late · usually 91% on time Riskiest UA 1140 IAD 18:00 → TPA 20:39 · 18% chance 15+ min late · usually 75% on time

Every nonstop on Thu, Oct 8

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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.


UA 683 United Flight history →	IAD 09:00	TPA 11:32	7%	3%	0.6%	91%
UA 2277 United Flight history →	IAD 12:49	TPA 15:15	15%	5%	0.7%	86%
UA 1140 United Flight history →	IAD 18:00	TPA 20:39	18%	6%	0.6%	75%

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 Thu, Oct 8 (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