UA3964 SingaporeSIN San FranciscoSFO
UA3964 by United Airlines flies from Singapore (SIN) to San Francisco (SFO).
scheduled from SIN
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions at SIN and SFO are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. 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 Singapore to San Francisco flights today
same route · United AirlinesIf UA3964 is cancelled, these are the other United Airlines nonstop flights from Singapore to San Francisco on the same day, with scheduled departure times in SIN local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How UA3964 actually runs
Pro Flight Search has tracked every published board update for UA3964 across the SIN and SFO boards: schedule changes, gate pushes and actual clocks. Combined risk score: 2.4/100. Based on airport operations, weather, and cached board history at SIN and SFO.
The verdict above is that record speaking, so it reflects how UA3964 operates rather than what the timetable promises. Numbers refresh as new flights operate.
Planning around UA3964? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — UA3964 Singapore to San Francisco on-time performance, measured from the SIN and SFO airport boards.
https://proflightsearch.com/flight/UA3964
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