Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 13 nonstops

Fri, Oct 9: DL 2127 at 06:00 is the safest bet, 6% chance of being 15+ min late; evening flights run 13–34%.

Safest bet that day DL 2127 IAD 06:00 → ATL 07:43 · 6% chance 15+ min late · usually 90% on time Riskiest F9 3691 IAD 20:33 → ATL 22:44 · 34% chance 15+ min late · usually 56% on time

Every nonstop on Fri, Oct 9

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	6%	3%	0.7%	90%
DL 1324 Delta Flight history →	IAD 10:21	ATL 12:05	8%	3%	0.7%	85%
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%	0.7%	83%
DL 1444 Delta Flight history →	IAD 12:37	ATL 14:28	12%	3%	0.7%	83%
UA 1635 United Flight history →	IAD 22:28	ATL 00:30	13%	5%	0.6%	75%
UA 471 United Flight history →	IAD 12:35	ATL 14:34	14%	4%	0.6%	86%
DL 2135 Delta Flight history →	IAD 15:02	ATL 16:53	14%	3%	0.7%	73%
DL 1695 Delta Flight history →	IAD 17:46	ATL 19:54	17%	4%	0.7%	74%
DL 2902 Delta Flight history →	IAD 19:26	ATL 21:26	17%	4%	0.8%	78%
UA 2081 United Flight history →	IAD 17:17	ATL 19:16	19%	7%	0.5%	70%
F9 4707 Frontier Flight history →	IAD 07:49	ATL 09:59	24%	9%	0.7%	71%
F9 3691 Frontier Flight history →	IAD 20:33	ATL 22:44	34%	15%	0.8%	56%

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 Fri, Oct 9 (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