UA520 San FranciscoSFO · 14:08 DenverDEN · 17:07
UA520 by United Airlines flies from San Francisco (SFO) to Denver (DEN) for the Thu, Sep 10 departure.
Same number through SFO → SLC → DEN
estimated arrival at DEN · local time · ~1h 49m from now
position updated 5m ago · checking again in 90s
Live position · flown path, last 4h 56m
Where the minutes go
last 4 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
Early read, sample still buildingConditions at SFO and DEN 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. This route's tracked sample is still thin — treat these as an early read, not a precise forecast.
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 Denver flights today
same route · United AirlinesIf UA520 is cancelled, these are the other United Airlines nonstop flights from San Francisco to Denver 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 UA520 actually runs
Pro Flight Search has tracked every published board update for UA520 across the SFO and DEN boards: schedule changes, gate pushes and actual clocks. Usually lands ~30 min late. Based on 2 confirmed landings · 1/2 within 15 min of schedule.
The verdict above is that record speaking, so it reflects how UA520 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: N814UA, N837UA.
Board clocks recorded as SFO and DEN published them.
Planning around UA520? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — UA520 San Francisco to Denver on-time performance, measured from the SFO and DEN airport boards.
https://proflightsearch.com/flight/UA520
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