Monday, October 5 · our forecast odds · issued Sun 5:00 PM ET · 15 nonstops

Tomorrow: UA 558 at 07:45 is the safest bet, 9% chance of being 15+ min late; evening flights run 24–30%.

Safest bet that day UA 558 DEN 07:45 → BOS 13:49 · 9% chance 15+ min late · usually 91% on time Riskiest B6 394 DEN 12:40 → BOS 18:37 · 37% chance 15+ min late · usually 68% on time

Against a calm day 23% average chance a nonstop arrives 15+ min late; 21% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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.


UA 558 United Flight history →	DEN 07:45	BOS 13:49	9%	3%	0.6%	91%
UA 2656 United Flight history →	DEN 00:12	BOS 06:11	9%	2%	0.2%	92%
UA 1232 United Flight history →	DEN 09:40	BOS 15:44	14%	4%	0.6%	86%
DL 499 Delta Flight history →	DEN 11:33	BOS 17:35	19%	6%	0.6%	75%
WN 3690 Southwest Flight history →	DEN 10:00	BOS 16:05	20%	4%	0.5%	83%
UA 597 United Flight history →	DEN 14:06	BOS 20:10	24%	10%	0.6%	71%
UA 1356 United Flight history →	DEN 17:40	BOS 23:44	24%	6%	0.6%	73%
B6 494 JetBlue Flight history →	DEN 09:54	BOS 15:57	25%	8%	0.6%	67%
WN 1494 Southwest Flight history →	DEN 19:05	BOS 01:05	26%	6%	0.6%	16%
WN 1553 Southwest	DEN 11:00	BOS 16:53	26%	4%	0.5%	no record
UA 2798 United Flight history →	DEN 16:03	BOS 22:06	26%	10%	0.6%	52%
UA 1912 United	DEN 15:40	BOS 21:28	28%	10%	0.6%	no record
B6 994 JetBlue Flight history →	DEN 23:37	BOS 05:30	30%	11%	0.6%	70%
WN 735 Southwest Flight history →	DEN 13:20	BOS 19:10	33%	8%	0.5%	38%
B6 394 JetBlue Flight history →	DEN 12:40	BOS 18:37	37%	16%	0.6%	68%

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 Mon, Oct 5 (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