Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · connections flying that day

Sun, Oct 11: United via Denver, leaving 05:00, is the safest bet: 83% chance of reaching Dulles on time; the tightest one-ticket connections make it only 69% of the time.

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Dulles on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (Dulles is 3 h ahead of Ontario). Layovers up to 4 hours. Pick a connection for its 12-month details.


United Details →	ONT 05:00 → DEN 08:20UA 2446	2h 00m Denver	DEN 10:20 → IAD 15:54UA 2087	7h 54m	98%	83%
United Details →	ONT 06:00 → SFO 07:25UA 2363	3h 25m San Francisco	SFO 10:50 → IAD 19:11UA 336	10h 11m	99%	75%
Delta Details →	ONT 11:48 → ATL 19:15DL 665	3h 38m Atlanta	ATL 22:53 → IAD 00:41 +1DL 2549	9h 53m	99%	74%
Delta Details →	ONT 11:59 → SEA 14:51DL 4070 · flown by SkyWest	1h 14m Seattle	SEA 16:05 → IAD 00:08 +1DL 541	9h 09m	92%	72%
Alaska Details →	ONT 18:56 → SEA 21:33AS 592	1h 10m Seattle	SEA 22:43 → IAD 06:39 +1AS 367	8h 43m	83%	64%
United Details →	ONT 06:57 → ORD 12:58UA 2226	1h 59m Chicago	ORD 14:57 → IAD 18:00UA 587	8h 03m	97%	63%
United Details →	ONT 13:50 → SFO 15:15UA 1375	1h 19m San Francisco	SFO 16:34 → IAD 00:55 +1UA 1453	8h 05m	82%	62%
American Details →	ONT 07:00 → DFW 12:09AA 2893	2h 42m Dallas-Fort Worth	DFW 14:51 → IAD 19:02AA 1863	9h 02m	97%	61%
Tight connection: often missed
Frontier Details →	ONT 20:15 → LAS 21:35F9 4206	1h 08m Las Vegas	LAS 22:43 → IAD 06:14 +1F9 3494	6h 59m	69%	44%

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