Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · connections flying that day

Sun, Oct 11: WN 4370 at 09:55 is the safest bet, 10% chance of being 15+ min late; the others run 43%.

Nonstops that day

All 2 nonstops →


WN 4370 Southwest	MDW 09:55	SLC 12:21	10%	2%	0.8%	no record
WN 3009 Southwest	MDW 21:35	SLC 00:00	43%	13%	3.1%	no record

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Salt Lake City on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (Salt Lake City is 1 h behind Chicago). Layovers up to 4 hours. Pick a connection for its 12-month details.


Delta Details →	MDW 09:54 → MSP 11:35DL 5469 · flown by Endeavor	2h 50m Minneapolis	MSP 14:25 → SLC 16:16DL 2658	7h 22m	98%	80%
Delta Details →	MDW 06:00 → ATL 08:57DL 1285	1h 13m Atlanta	ATL 10:10 → SLC 12:10DL 387	7h 10m	94%	78%
Delta Details →	MDW 13:26 → DTW 15:44DL 4688 · flown by Endeavor	3h 18m Detroit	DTW 19:02 → SLC 20:59DL 8771	8h 33m	94%	66%
Delta Details →	MDW 13:49 → MSP 15:33DL 4820 · flown by Endeavor	2h 40m Minneapolis	MSP 18:13 → SLC 20:07DL 2607	7h 18m	89%	64%
Delta Details →	MDW 11:05 → ATL 14:01DL 1063	1h 19m Atlanta	ATL 15:20 → SLC 17:18DL 526	7h 13m	92%	63%
Delta Details →	MDW 12:41 → ATL 15:43DL 2417	3h 51m Atlanta	ATL 19:34 → SLC 21:37DL 660	9h 56m	98%	62%
Delta Details →	MDW 17:10 → ATL 20:22DL 1728	2h 03m Atlanta	ATL 22:25 → SLC 00:26 +1DL 453	8h 16m	92%	57%
Tight connection: often missed
Frontier Details →	MDW 12:45 → DFW 15:18F9 2999	52m Dallas-Fort Worth	DFW 16:10 → SLC 18:04F9 3277	6h 19m	69%	39%

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