Schedule: a typical summer Monday (the flights of Jul 27, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.

UNITED · FLIGHT UA 1531 SCHEDULED · TYPICAL SCHEDULE

Monday, October 5 Tomorrow

UA 1531 · ORD → SAN

departs 8:05 PM CT · arrives 10:34 PM PT

Forecast issued Sun 7:00 AM ET · 38h before departure

Arrive at SAN more than 15 minutes late?

14% chance · ±3 pts +3 pts · 24h

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

How late will it get to SAN?

On time or early
85%
15–30 min late
6%
30 min–1 hour late
3%
1–2 hours late
3%
Over 2 hours late
1%
Cancelled
<1%

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

What’s moving the odds

↑ 8pm departures from ORD are often late

↑ Later flights pick up delays from earlier in the day

↑ Arrivals into SAN at that hour are often late

↓ Mostly benign weather forecast at ORD

↓ Mondays in October are usually quieter than average

Weather at each end

ORD (origin) Gusts9 kt Ceilingnone (clear) Visibility10+ mi Precipnone

SAN (destination) Gusts16 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 1531 · ORD → SAN

Odds over time

How late will it get to SAN?