Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 8:00 PM ET · connections flying that day

Sun, Oct 11: UA 4251 at 06:00 is the safest bet, 8% chance of being 15+ min late; the others run 19%.

Nonstops that day

All 2 nonstops →


UA 4251 United flown by CommuteAir Flight history →	GSO 06:00	IAD 07:18	8%	2%	1.4%	91%
UA 4819 United flown by CommuteAir Flight history →	GSO 14:58	IAD 16:37	19%	4%	1.9%	75%

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. Layovers up to 4 hours. Pick a connection for its 12-month details.


Delta Details →	GSO 05:25 → ATL 06:38DL 3018	1h 05m Atlanta	ATL 07:43 → IAD 09:26DL 1324	4h 01m	96%	87%
Delta Details →	GSO 06:35 → ATL 07:56DL 3004	1h 58m Atlanta	ATL 09:54 → IAD 11:41DL 1444	5h 06m	98%	82%
Delta Details →	GSO 10:14 → ATL 11:31DL 3173	1h 24m Atlanta	ATL 12:55 → IAD 14:39DL 2135	4h 25m	96%	81%
Delta Details →	GSO 06:25 → DTW 08:04DL 5088 · flown by Endeavor	46m Detroit	DTW 08:50 → IAD 10:23DL 2884	3h 58m	90%	80%
Delta Details →	GSO 11:20 → DTW 13:00DL 4966 · flown by Endeavor	2h 08m Detroit	DTW 15:08 → IAD 16:41DL 1787	5h 21m	98%	75%
Delta Details →	GSO 12:20 → ATL 13:49DL 3052	2h 50m Atlanta	ATL 16:39 → IAD 18:31DL 2902	6h 11m	100%	74%
Delta Details →	GSO 18:35 → ATL 20:09DL 3050	2h 44m Atlanta	ATL 22:53 → IAD 00:41 +1DL 2549	6h 06m	98%	72%
American Details →	GSO 07:05 → DFW 09:15AA 2846	54m Dallas-Fort Worth	DFW 10:09 → IAD 14:03AA 524	6h 58m	91%	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 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