Houston IAH: On-Time Departures

How reliable is Houston's IAH for departures? The on-time and cancellation numbers it actually delivered last month, from U.S. government flight data.

What IAH actually delivered

In May 2026, 75.5% of the 10,105 flights scheduled to depart Houston's IAH pushed back within 15 minutes of schedule, and 0.46% were cancelled — putting IAH at the middle of the major US airports that month (#17 of 30 major US airports). These figures are computed by The Sales Traveler from the raw U.S. DOT Bureau of Transportation Statistics on-time dataset. On-time departure = flights that pushed back within 15 minutes of schedule (DepDel15=0), as a share of non-cancelled departures from the airport. Cancellation rate = cancelled flights divided by scheduled departures. Major US airports only (>=15,000 scheduled departures in the month). Computed by The Sales Traveler from the raw BTS on-time dataset for the month.

What that means for a business trip through IAH

Departing on time is the number that decides whether you make a connection or a same-day return. IAH sits mid-pack — treat it like any large hub: buffer the schedule and keep a plan B for the meeting that matters. Departure reliability shifts month to month with weather and operations, so this updates as new DOT data publishes. For live conditions, see the flight-delay tracker.

Which airline you fly still matters

Airport reliability sets the baseline; the carrier you book moves it. The same departure bank can run smoothly for one airline and poorly for another. Cross-reference this with the airline reliability scorecards — on-time and cancellation rates for every major US carrier, computed from the same U.S. DOT record — before you book a schedule-critical trip through IAH.