Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 11 nonstops

Fri, Oct 9: DL 1285 at 06:00 is the safest bet, 5% chance of being 15+ min late; evening flights run 12–24%.

Safest bet that day DL 1285 MDW 06:00 → ATL 08:57 · 5% chance 15+ min late · usually 90% on time Riskiest WN 4140 MDW 18:50 → ATL 21:50 · 24% chance 15+ min late · usually 36% 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 1285 Delta Flight history →	MDW 06:00	ATL 08:57	5%	2%	0.6%	90%
WN 3054 Southwest Flight history →	MDW 07:15	ATL 10:05	7%	1%	0.6%	93%
DL 1063 Delta Flight history →	MDW 11:05	ATL 14:01	8%	2%	0.7%	90%
DL 2417 Delta Flight history →	MDW 12:41	ATL 15:43	9%	2%	0.7%	86%
WN 4154 Southwest Flight history →	MDW 08:55	ATL 11:45	9%	2%	0.6%	86%
DL 1728 Delta Flight history →	MDW 17:10	ATL 20:22	12%	3%	0.7%	74%
F9 2292 Frontier Flight history →	MDW 06:05	ATL 09:22	17%	5%	1.0%	71%
WN 4606 Southwest Flight history →	MDW 11:00	ATL 13:50	17%	2%	0.6%	38%
WN 4592 Southwest Flight history →	MDW 14:40	ATL 17:35	19%	5%	0.6%	41%
F9 2144 Frontier Flight history →	MDW 12:11	ATL 15:13	22%	7%	1.0%	68%
WN 4140 Southwest Flight history →	MDW 18:50	ATL 21:50	24%	6%	0.6%	36%

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