Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 13 nonstops

Fri, Oct 9: UA 647 at 07:45 is the safest bet, 7% chance of being 15+ min late; evening flights run 22–43%.

Safest bet that day UA 647 BOS 07:45 → DEN 10:19 · 7% chance 15+ min late · usually 91% on time Riskiest WN 742 BOS 17:30 → DEN 20:10 · 43% chance 15+ min late · usually 29% on time

Every nonstop on Fri, Oct 9

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 647 United Flight history →	BOS 07:45	DEN 10:19	7%	2%	0.6%	91%
WN 4156 Southwest Flight history →	BOS 06:25	DEN 08:50	7%	1%	0.6%	88%
DL 499 Delta Flight history →	BOS 07:45	DEN 10:21	8%	3%	0.6%	85%
UA 662 United Flight history →	BOS 09:40	DEN 12:12	9%	2%	0.6%	91%
UA 414 United Flight history →	BOS 12:22	DEN 14:53	12%	3%	0.6%	90%
B6 493 JetBlue Flight history →	BOS 06:30	DEN 09:03	17%	3%	0.7%	87%
UA 2297 United Flight history →	BOS 15:10	DEN 17:55	17%	6%	0.6%	86%
WN 4208 Southwest Flight history →	BOS 11:35	DEN 14:05	21%	3%	0.5%	70%
B6 793 JetBlue Flight history →	BOS 11:20	DEN 13:55	22%	5%	0.7%	60%
UA 800 United Flight history →	BOS 16:57	DEN 19:45	22%	7%	0.6%	75%
UA 2433 United Flight history →	BOS 20:39	DEN 23:26	22%	5%	0.6%	56%
B6 993 JetBlue Flight history →	BOS 19:59	DEN 22:41	35%	9%	0.7%	60%
WN 742 Southwest Flight history →	BOS 17:30	DEN 20:10	43%	10%	0.6%	29%

Alternatives with one stop that day

All connections →


Delta Details →	BOS 05:30 → DTW 07:38DL 1019	1h 02m Detroit	DTW 08:40 → DEN 09:47DL 1113	6h 17m	96%	86%
United Details →	BOS 05:45 → IAD 07:23UA 1734	52m Dulles	IAD 08:15 → DEN 10:10UA 792	6h 25m	93%	86%
Delta Details →	BOS 05:55 → MSP 08:04DL 2303	51m Minneapolis	MSP 08:55 → DEN 10:03DL 2849	6h 08m	94%	83%

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 Fri, Oct 9 (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