Today: only flights still to leave (it’s 8:43 pm at Chicago); 11 already left

Sunday, October 4 · our forecast odds · issued Sun 8:00 PM ET · connections flying that day

Today: one nonstop, AA 4640 at 21:18, with a 26% chance of arriving 15+ min late.

Nonstops today


AA 4640 American flown by Republic Flight history →	ORD 21:18	MDT 00:22	26%	9%	0.6%	80%

Best connections today, one ticket

Most reliable Quickest (80%+ on time)

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

No one-ticket connection fits with layovers up to 4 hours that day. Try any airlines.

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 Sun, Oct 4 (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