UA540 San FranciscoSFO · 12:35 San DiegoSAN · 16:25
UA540 by United Airlines flies from San Francisco (SFO) to San Diego (SAN) for the Mon, Sep 7 departure.
Same number through SFO → DEN → SAN
arrived at SAN · on schedule
Where the minutes go
last 3 operations · gate push → arrivalThe bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions at SFO and SAN 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 San Francisco to San Diego flights today
same route · United AirlinesIf UA540 is cancelled, these are the other United Airlines nonstop flights from San Francisco to San Diego 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 UA540 actually runs
Pro Flight Search has tracked every published board update for UA540 across the SFO and SAN boards: schedule changes, gate pushes and actual clocks. Early read — pattern not clear yet. Only 3 completed legs so far: left right on schedule but landed about 19 min early. Not enough to call it.
The verdict above is that record speaking, so it reflects how UA540 operates rather than what the timetable promises. Numbers refresh as new flights operate.
How this operation is measured
Board log
scheduled → actual, per operationAircraft
Recent tails: N34551, N14507, N24573.
Board clocks recorded as SFO and SAN published them.
Planning around UA540? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — UA540 San Francisco to San Diego on-time performance, measured from the SFO and SAN airport boards.
https://proflightsearch.com/flight/UA540
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