SEA to IAH flight delays
Seattle, WA (SEA) Houston, TX (IAH) · 1,874 miles
217 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics
85.12%
Arrived on time
Within 15 minutes of schedule
0%
Cancelled
Share of scheduled flights
82 min
When late, late by
Average across delayed arrivals
13 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The shape of the lateness matters here. Flights on this route are not late often, but when they are late they are late by about 82 minutes — long enough to lose a connection or an evening. The on-time percentage looks reassuring and understates the consequence of being on the wrong flight.
The two directions do not behave alike. IAH to SEA arrives on time 10.9 points less often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
This route does better than its own airport. Departures from SEA overall run 10.8 points less punctual than this particular one — so whatever congestion SEA has, this route is largely escaping it.
Only United Airlines flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.
Which airline should you fly on this route?
Over March 2025 – August 2026, United Airlines arrived on time most often on SEA to IAH.
Every airline on SEA to IAH
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| United Airlines | 130 | 87.6% | 0% | 84 min | A |
| Alaska Airlines | 87 | 81.4% | 0% | 81 min | — |
The return leg
IAH to SEA Houston back to Seattle 74.19% on time COther routes from Seattle
Common questions
Are flights from Seattle to Houston usually delayed?
85.12% of flights on the SEA to IAH route arrived within 15 minutes of schedule, so roughly 1 in every ten arrived late. That is better than the average route in this record.
Which airlines fly from Seattle to Houston?
Only United Airlines appears in the published record on this route, with 130 flights and 87.6% arriving on time.
How often are SEA to IAH flights cancelled?
0% of scheduled flights did not operate — about 1 in every thousand. That is in the normal range.
When SEA to IAH flights are late, how late are they?
About 82 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on SEA to IAH during March 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →