Saturday, October 10 · typical odds for a Saturday (too early for a weather forecast) · issued Sun 8:00 PM ET · connections flying that day

Sat, Oct 10 looks like a normal day here: all 2 nonstops are 3–10% likely to arrive 15+ min late.

Nonstops that day

All 2 nonstops →


WN 1947 Southwest	GRR 06:59	MDW 07:20	3%	1%	0.6%	no record
WN 1221 Southwest	GRR 14:44	MDW 15:00	10%	3%	0.6%	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 1 h behind Grand Rapids). Layovers up to 4 hours. Pick a connection for its 12-month details.


Delta Details →	GRR 06:30 → ATL 08:31DL 2453	1h 09m Atlanta	ATL 09:40 → MDW 10:42DL 2417	5h 12m	95%	83%
Delta Details →	GRR 05:30 → DTW 06:30DL 4885 · flown by Endeavor	2h 20m Detroit	DTW 08:50 → MDW 09:14DL 4684 · flown by Endeavor	4h 44m	95%	70%
Delta Details →	GRR 10:34 → DTW 11:33DL 3500 · flown by SkyWest	52m Detroit	DTW 12:25 → MDW 12:46DL 4688 · flown by Endeavor	3h 12m	80%	64%
Delta Details →	GRR 07:00 → MSP 07:32DL 2913	3h 58m Minneapolis	MSP 11:30 → MDW 13:09DL 4820 · flown by Endeavor	7h 09m	99%	59%

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 Sat, Oct 10 (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