UA4040 HoustonIAH LouisvilleSDF
UA4040 by United Airlines flies from Houston (IAH) to Louisville (SDF).
scheduled from IAH
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions at IAH and SDF 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 Houston to Louisville flights today
same route · United AirlinesIf UA4040 is cancelled, these are the other United Airlines nonstop flights from Houston to Louisville on the same day, with scheduled departure times in IAH local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How UA4040 actually runs
Pro Flight Search has tracked every published board update for UA4040 across the IAH and SDF boards: schedule changes, gate pushes and actual clocks. Combined risk score: 33.0/100. Based on airport operations, weather, and cached board history at IAH and SDF.
The verdict above is that record speaking, so it reflects how UA4040 operates rather than what the timetable promises. Numbers refresh as new flights operate.
Planning around UA4040? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — UA4040 Houston to Louisville on-time performance, measured from the IAH and SDF airport boards.
https://proflightsearch.com/flight/UA4040
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