Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 8:00 PM ET · 22 nonstops

Sun, Oct 11: WN 3873 at 05:05 is the safest bet, 3% chance of being 15+ min late; evening flights run 26–53%.

Safest bet that day WN 3873 SLC 05:05 → DEN 06:36 · 3% chance 15+ min late Riskiest WN 3877 SLC 16:45 → DEN 18:15 · 53% chance 15+ min late

Every nonstop on Sun, Oct 11

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.


WN 3873 Southwest	SLC 05:05	DEN 06:36	3%	1%	0.7%	no record
UA 5683 United flown by SkyWest Flight history →	SLC 05:15	DEN 06:54	6%	3%	0.7%	95%
WN 4117 Southwest	SLC 08:10	DEN 09:40	7%	3%	0.6%	no record
UA 1232 United Flight history →	SLC 07:00	DEN 08:42	10%	5%	0.6%	95%
UA 5642 United flown by SkyWest Flight history →	SLC 08:30	DEN 10:27	12%	5%	0.7%	81%
DL 1317 Delta Flight history →	SLC 07:45	DEN 09:12	12%	3%	0.6%	95%
WN 3875 Southwest	SLC 11:30	DEN 13:00	15%	4%	0.6%	no record
DL 1553 Delta Flight history →	SLC 10:15	DEN 11:47	15%	4%	0.6%	84%
UA 4720 United flown by SkyWest Flight history →	SLC 13:05	DEN 14:51	18%	7%	0.9%	92%worse than usual
UA 2090 United	SLC 10:31	DEN 12:03	21%	7%	0.6%	no record
F9 3862 Frontier Flight history →	SLC 08:16	DEN 10:01	23%	6%	0.8%	81%
F9 3220 Frontier Flight history →	SLC 11:29	DEN 13:06	24%	7%	0.8%	84%
WN 4718 Southwest	SLC 13:05	DEN 14:35	26%	7%	0.8%	no record
DL 1667 Delta Flight history →	SLC 21:05	DEN 22:40	26%	8%	1.8%	79%
OO 5752 SkyWest	SLC 18:07	DEN 19:58	35%	15%	4.0%	no record
WN 3854 Southwest	SLC 19:35	DEN 21:06	41%	15%	3.2%	no record
UA 1955 United	SLC 19:05	DEN 20:36	42%	18%	4.1%	no record
DL 1586 Delta Flight history →	SLC 18:30	DEN 20:01	44%	16%	3.8%	71%worse than usual
UA 1662 United Flight history →	SLC 14:28	DEN 16:11	45%	17%	0.8%	79%worse than usual
DL 1623 Delta Flight history →	SLC 15:24	DEN 16:53	45%	13%	0.9%	85%worse than usual
F9 4236 Frontier Flight history →	SLC 16:09	DEN 17:47	48%	18%	1.7%	77%worse than usual
WN 3877 Southwest	SLC 16:45	DEN 18:15	53%	16%	1.2%	no record

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 Sun, Oct 11 (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