UA3999United Airlines · ATL → IAH
live · 9m ago
Route confirmed United Airlines

UA3999 AtlantaATL HoustonIAH

UA3999 by United Airlines flies from Atlanta (ATL) to Houston (IAH).

Right nowNext departure tomorrow Operates daily
09:30

scheduled from ATL

The route today

live boards
ATLAtlantaOn-time likelyATL delay board →
IAHHoustonOn-time likelyIAH delay board →
ATL→IAHevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
24%Chance of 15+ min delay
1.1%Chance of cancellation
-2 minTypical airport delay in this weather

Conditions at ATL and IAH are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. These figures come from both airports' records 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 →

Tomorrow at Atlanta

Forecast

Wed 11 Nov, local date

High21°Clikely 20°C to 22°C
Low10°Clikely 9°C to 11°C

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

Tomorrow at Houston

Forecast

Wed 11 Nov, local date

High25°Clikely 22°C to 27°C
Low17°Clikely 14°C to 18°C
  • 76% chance of rain

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other Atlanta to Houston flights today

same route · United Airlines
UA532departs 07:00
UA2212departs 09:20
UA3997departs 09:20
UA4053departs 11:31
UA411departs 11:31
UA521departs 15:57

If UA3999 is cancelled, these are the other United Airlines nonstop flights from Atlanta to Houston on the same day, with scheduled departure times in ATL local time. Most flights that show a delay still operate. Rebooking usually helps only when that delay is very large. Every airline on this route →

How UA3999 actually runs

Pro Flight Search has tracked every published board update for UA3999 across the ATL and IAH boards: schedule changes, gate pushes and actual clocks. Combined risk score: 33.0/100. Based on airport operations, weather, and cached board history at ATL and IAH.

The verdict above is that record speaking, so it reflects how UA3999 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Planning around UA3999? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search: UA3999 Atlanta to Houston on-time performance, measured from the ATL and IAH airport boards.

Canonical URL
https://proflightsearch.com/flight/UA3999
How we measure this →