Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 8:00 PM ET · connections flying that day

Sun, Oct 11: Delta via Minneapolis, leaving 06:00, is the safest bet: 83% chance of reaching Chicago on time.

Nonstops that day

All 2 nonstops →


WN 3319 Southwest	PDX 05:20	MDW 11:21	4%	1%	0.9%	no record
WN 3320 Southwest	PDX 23:35	MDW 05:41	17%	5%	1.1%	no record

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Chicago on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (Chicago is 2 h ahead of Portland). Layovers up to 4 hours. Pick a connection for its 12-month details.


Delta Details →	PDX 00:33 → MSP 05:49DL 2359	1h 42m Minneapolis	MSP 07:31 → MDW 09:13DL 4712 · flown by Endeavor	6h 40m	99%	92%
Delta Details →	PDX 06:00 → MSP 11:14DL 2369	56m Minneapolis	MSP 12:10 → MDW 13:52DL 4820 · flown by Endeavor	5h 52m	93%	83%
Delta Details →	PDX 11:37 → ATL 19:19DL 539	1h 56m Atlanta	ATL 21:15 → MDW 22:15DL 1076	8h 38m	96%	68%
Delta Details →	PDX 06:35 → ATL 14:14DL 662	1h 01m Atlanta	ATL 15:15 → MDW 16:15DL 1728	7h 40m	93%	67%

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