Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · connections flying that day

Thu, Oct 8: Delta via Atlanta, leaving 12:07, is the safest bet: 83% chance of reaching San Juan on time.

Nonstops that day

All 1 nonstop →


UA 1339 United Flight history →	DEN 09:43	SJU 17:38	14%	4%	0.6%	84%

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach San Juan on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (San Juan is 2 h ahead of Denver). Layovers up to 4 hours. Pick a connection for its 12-month details.


United Details →	DEN 07:42 → IAH 11:15UA 1720	3h 48m Houston	IAH 15:03 → SJU 20:38UA 701	10h 56m	100%	86%
Delta Details →	DEN 05:45 → ATL 10:44DL 341	2h 16m Atlanta	ATL 13:00 → SJU 16:39DL 1946	8h 54m	99%	85%
Delta Details →	DEN 10:52 → ATL 15:52DL 346	2h 53m Atlanta	ATL 18:45 → SJU 22:29DL 1861	9h 37m	100%	85%
United Details →	DEN 05:00 → IAH 08:32UA 320	1h 31m Houston	IAH 10:03 → SJU 15:42UA 1192	8h 42m	99%	83%
Frontier Details →	DEN 06:00 → MCO 11:47F9 4646	1h 57m Orlando	MCO 13:44 → SJU 16:49F9 1824	8h 49m	99%	77%
American Details →	DEN 05:00 → DFW 08:05AA 2612	1h 21m Dallas-Fort Worth	DFW 09:26 → SJU 15:31AA 702	8h 31m	97%	76%
United Details →	DEN 00:02 → EWR 06:04UA 1745	1h 56m Newark	EWR 08:00 → SJU 12:04UA 2143	10h 02m	99%	75%
Frontier Details →	DEN 10:36 → MCO 16:30F9 3312	3h 42m Orlando	MCO 20:12 → SJU 23:22F9 2868	10h 46m	99%	71%

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