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

Fri, Oct 9: DL 859 at 06:05 is the safest bet, 7% chance of being 15+ min late; evening flights run 21–41%.

Safest bet that day DL 859 BOS 06:05 → SLC 09:17 · 7% chance 15+ min late · usually 89% on time Riskiest B6 247 BOS 19:32 → SLC 22:59 · 41% chance 15+ min late · usually 58% 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.


DL 859 Delta Flight history →	BOS 06:05	SLC 09:17	7%	2%	0.6%	89%
DL 464 Delta Flight history →	BOS 11:15	SLC 14:20	13%	3%	0.6%	78%
DL 445 Delta Flight history →	BOS 18:45	SLC 22:11	21%	7%	0.6%	72%
B6 247 JetBlue Flight history →	BOS 19:32	SLC 22:59	41%	15%	1.0%	58%

Alternatives with one stop that day

All connections →


Southwest Details →	BOS 06:25 → DEN 08:50WN 4156	1h 15m Denver	DEN 10:05 → SLC 11:45WN 4027	7h 20m	97%	87%
Delta Details →	BOS 08:45 → CVG 11:12DL 5601 · flown by Republic	1h 18m Hebron	CVG 12:30 → SLC 14:14DL 678	7h 29m	96%	86%
Delta Details →	BOS 05:30 → DTW 07:38DL 1019	47m Detroit	DTW 08:25 → SLC 10:21DL 698	6h 51m	92%	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