UA421 DenverDEN · 15:40 ChicagoORD · 21:08
UA421 by United Airlines flies from Denver (DEN) to Chicago (ORD) for the Wed, Sep 9 departure.
Same number through DEN → IAD → ORD
arrived at ORD · 21 min early
Where the minutes go
last 7 operations · gate push → arrivalThe bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.
The last 30 days
arrival outcome per operation0 cancelled · 8 operations tracked
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions at DEN and ORD 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 Denver to Chicago flights today
same route · United AirlinesIf UA421 is cancelled, these are the other United Airlines nonstop flights from Denver to Chicago on the same day, with scheduled departure times in DEN local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How UA421 actually runs
Pro Flight Search has tracked every published board update for UA421 across the DEN and ORD boards: schedule changes, gate pushes and actual clocks. Usually lands ~12 min early. Based on 8 confirmed landings · 7/8 within 15 min of schedule. Pushes back late but makes up time in the air.
The verdict above is that record speaking, so it reflects how UA421 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: N24516, N14569, N14521, N14506.
Board clocks recorded as DEN and ORD published them.
Planning around UA421? 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 — UA421 Denver to Chicago on-time performance, measured from the DEN and ORD airport boards.
https://proflightsearch.com/flight/UA421
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