Schedule: a typical summer Sunday (the flights of Jul 26, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.

UNITED · FLIGHT UA 1639 SCHEDULED · TYPICAL SCHEDULE

Sunday, October 4 Tomorrow

UA 1639 · STL → ORD

departs 5:59 PM CT · arrives 7:30 PM CT

Forecast issued Sat 1:00 PM ET · 30h before departure

Arrive at ORD more than 15 minutes late?

30% chance · ±2 pts +6 pts · 24h

HOW SURE WE ARE Moderate. The odds now blend history with early weather forecasts.

How late will it get to ORD?

On time or early
70%
15–30 min late
12%
30 min–1 hour late
8%
1–2 hours late
7%
Over 2 hours late
3%
Cancelled
<1%

Gate arrival compared with the scheduled arrival. The ranges add up to 100%.

What’s moving the odds

↑ Arrivals into ORD at that hour are often late

↑ Later flights pick up delays from earlier in the day

↑ This flight has been late 31% of the time recently

↓ Mostly benign weather forecast at ORD

↓ Mostly benign weather forecast at STL

Weather at each end

STL (origin) Gusts11 kt Ceilingnone (clear) Visibility10+ mi Precipnone

ORD (destination) Gusts12 kt Ceilingnone (clear) Visibility10+ mi Precipnone

How this resolves

Yes if the gate arrival is more than 15 minutes after the scheduled arrival. Cancelled or diverted flights resolve N/A.

Every question here is display only — there is no betting or money involved. Gate times come from the airline; a cancellation resolves only the “Cancelled?” question, and a diversion voids the delay questions.

UA 1639 · STL → ORD

Odds over time

How late will it get to ORD?