Today: DL 1626 at 06:30 is the safest bet, 6% chance of being 15+ min late; evening flights run 9–22%.

Safest bet today DL 1626 STL 06:30 → DTW 09:04 · 6% chance 15+ min late · usually 92% on time Riskiest WN 4822 STL 19:55 → DTW 22:30 · 22% chance 15+ min late · usually 46% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 10% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, 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 1626 Delta Flight history →	STL 06:30	DTW 09:04	6%	3%	0.5%	92%
WN 645 Southwest	STL 10:20	DTW 12:57	9%	2%	0.1%	no record
DL 2868 Delta Flight history →	STL 10:19	DTW 12:53	9%	4%	0.4%	92%
DL 1371 Delta Flight history →	STL 13:54	DTW 16:30	9%	3%	0.7%	77%
DL 2822 Delta Flight history →	STL 18:09	DTW 20:44	9%	4%	0.7%	76%
WN 4177 Southwest Flight history →	STL 09:55	DTW 12:25	11%	2%	0.1%	76%
WN 3239 Southwest	STL 19:50	DTW 22:27	18%	5%	0.5%	no record
WN 4822 Southwest Flight history →	STL 19:55	DTW 22:30	22%	5%	0.5%	46%

How these are worked out. Each flight’s odds are our forecast for that day; 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 Mon, Oct 5 (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