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: WN 1270 at 08:00 is the safest bet, 8% chance of being 15+ min late; evening flights run 19–32%.

Safest bet that day WN 1270 ATL 08:00 → MDW 08:55 · 8% chance 15+ min late · usually 78% on time Riskiest WN 233 ATL 19:35 → MDW 20:30 · 32% chance 15+ min late · usually 31% 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.


WN 1270 Southwest Flight history →	ATL 08:00	MDW 08:55	8%	1%	0.6%	78%
DL 1063 Delta Flight history →	ATL 09:09	MDW 10:05	11%	2%	0.7%	88%
DL 2417 Delta Flight history →	ATL 11:00	MDW 11:56	11%	2%	0.7%	88%
WN 224 Southwest Flight history →	ATL 10:00	MDW 11:00	12%	2%	0.6%	89%
DL 1728 Delta Flight history →	ATL 15:15	MDW 16:15	16%	4%	0.7%	77%
WN 225 Southwest Flight history →	ATL 12:30	MDW 13:25	17%	3%	0.6%	76%
DL 1076 Delta Flight history →	ATL 21:15	MDW 22:15	19%	5%	0.6%	77%
WN 232 Southwest Flight history →	ATL 17:55	MDW 18:55	25%	7%	0.6%	48%
F9 2779 Frontier Flight history →	ATL 10:05	MDW 11:07	25%	7%	1.0%	64%
F9 2291 Frontier Flight history →	ATL 20:59	MDW 22:03	30%	14%	1.0%	68%
WN 233 Southwest Flight history →	ATL 19:35	MDW 20:30	32%	8%	0.6%	31%

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