UA3940 San FranciscoSFO ChicagoORD
UA3940 by United Airlines flies from San Francisco (SFO) to Chicago (ORD).
scheduled from SFO
The route today
live boardsWeather lens
Weather-conditioned outlook for this flight right now
Measured, 90-day sampleDriven mainly by SFO (San Francisco), currently flying MVFR (marginal visual). For this route and airline, under conditions like today's, over the last 90 days.
Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →
When it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
Other San Francisco to Chicago flights today
same route · United AirlinesIf UA3940 is cancelled, these are the other United Airlines nonstop flights from San Francisco to Chicago on the same day, with scheduled departure times in SFO local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How UA3940 actually runs
Pro Flight Search has tracked every published board update for UA3940 across the SFO and ORD boards: schedule changes, gate pushes and actual clocks. Combined risk score: 33.0/100. Based on airport operations, weather, and cached board history at SFO and ORD.
The verdict above is that record speaking, so it reflects how UA3940 operates rather than what the timetable promises. Numbers refresh as new flights operate.
Planning around UA3940? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Pro Flight Search — UA3940 San Francisco to Chicago on-time performance, measured from the SFO and ORD airport boards.
https://proflightsearch.com/flight/UA3940
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