Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 4 nonstops

Thu, Oct 8: F9 686 at 07:30 is the safest bet, 11% chance of being 15+ min late; the others run 13–22%.

Safest bet that day F9 686 DEN 07:30 → DCA 12:51 · 11% chance 15+ min late · usually 95% on time Riskiest F9 690 DEN 16:28 → DCA 21:59 · 22% chance 15+ min late · usually 67% 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.


F9 686 Frontier Flight history →	DEN 07:30	DCA 12:51	11%	4%	0.7%	95%
UA 789 United Flight history →	DEN 09:30	DCA 14:59	13%	5%	0.6%	91%
F9 688 Frontier Flight history →	DEN 11:25	DCA 16:59	21%	7%	0.7%	78%
F9 690 Frontier Flight history →	DEN 16:28	DCA 21:59	22%	10%	0.7%	67%

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