Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · 13 nonstops

Sun, Oct 11: DL 2127 at 06:00 is the safest bet, 7% chance of being 15+ min late; evening flights run 21–38%.

Safest bet that day DL 2127 IAD 06:00 → ATL 07:43 · 7% chance 15+ min late · usually 90% on time Riskiest F9 4409 IAD 20:51 → ATL 22:54 · 38% chance 15+ min late · usually 59% on time

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.


DL 2127 Delta Flight history →	IAD 06:00	ATL 07:43	7%	3%	0.8%	90%
UA 2739 United Flight history →	IAD 08:15	ATL 10:14	9%	3%	0.6%	89%
DL 3080 Delta Flight history →	IAD 08:27	ATL 10:18	9%	3%	0.8%	83%
DL 1324 Delta Flight history →	IAD 10:21	ATL 12:05	10%	3%	0.8%	85%
DL 1444 Delta Flight history →	IAD 12:39	ATL 14:30	14%	4%	0.8%	83%
UA 471 United Flight history →	IAD 12:35	ATL 14:34	17%	5%	0.6%	86%
DL 2135 Delta Flight history →	IAD 15:45	ATL 17:36	20%	5%	1.0%	73%
UA 1357 United	IAD 22:43	ATL 00:42	21%	7%	0.7%	no record
DL 2902 Delta Flight history →	IAD 19:26	ATL 21:27	22%	5%	1.1%	78%
DL 1695 Delta Flight history →	IAD 18:07	ATL 20:14	22%	5%	1.0%	74%
F9 4707 Frontier Flight history →	IAD 07:49	ATL 09:59	24%	9%	0.8%	71%
UA 2081 United Flight history →	IAD 17:17	ATL 19:16	28%	8%	0.8%	70%
F9 4409 Frontier Flight history →	IAD 20:51	ATL 22:54	38%	14%	1.3%	59%

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