SEA to IAH flight delays

SEA IAH Seattle Tacoma to George Bush · 1,874 miles

6,298 flights were scheduled from SEA to IAH over July 2023 through June 2026. Of the 6,196 that made the trip, 79.3% reached the gate less than 15 minutes behind schedule. These are arrival figures: “on time” means the flight reached the gate less than 15 minutes behind schedule. Arrivals are what decide whether you make the connection, so route and airline pages are scored on them rather than on pushback.

Data through June 2026 · Bureau of Transportation Statistics

The route in brief

Flights in the window
6,298
Arrived on time
79.3%
Cancelled
1.2%
Scheduled distance
1,874 miles

Cancellations are counted against everything scheduled. Diverted flights are counted with them rather than as very late arrivals, which is why the on-time share and the cancellation rate do not add up to everything that happened.

Airline by airline

Airlines with at least 100 flights on SEA–IAH, busiest first. Same route, same weather, same air traffic — which makes this the fairest comparison on the site.

Airline Arrived on time Typical delay Cancelled Flights
United Airlines 83.2% 73 min 1.3% 3,668
Alaska Airlines 73.9% 43 min 1.2% 2,627

Month by month

July was the month to avoid on SEA–IAH: 67.9% of flights arrived on time, against 90.3% in February. Each bar pools three years of that calendar month.

Share of flights that arrived on time, by calendar month. Best month in green, worst in amber. The hairline sits at the overall rate, 79.3%.
Arrival on-time share, SEA to IAH, by calendar month
Month Share flights that arrived on time Flights
January 81.7% 405
February 90.3% 340
March 80.4% 444
April 81.5% 463
May 77.5% 585
June 74.3% 658
July 67.9% 696
August 74.1% 674
September 84.6% 580
October 85.9% 526
November 83% 449
December 81.3% 478

Both ends of the route

A route’s record is built out of two airports’ habits. The hour-by-hour grid for each is on its own page.

SEA to IAH in one number

SEA → IAH

When a flight on this route was late, it was late by about 57 min.

July 2023–June 2026 · 6,298 flights

79.3% of flights arrived on time

Questions about SEA to IAH

Which airline is most reliable from SEA to IAH?
United Airlines — its flights on this pairing arrived on time 83.2% of the time, with 3,668 scheduled. Alaska Airlines came in at 73.9% over 2,627 scheduled. Airlines with fewer than 100 flights on the route are not rated.
What is the worst month to fly SEA to IAH?
July, at 67.9% of arrivals on time, with 696 flights scheduled. February was the best of the year at 90.3%.
How late are SEA–IAH flights when they are late?
57 min on average, counting only the flights that arrived 15 minutes or more behind schedule. The on-time flights are left out of that average on purpose — mixing them in would flatter it.
How often is the SEA to IAH flight cancelled?
1.2% of scheduled flights on this route were cancelled, July 2023 through June 2026. Diverted flights are counted with the cancellations rather than as late arrivals.
Are these departure or arrival numbers?
Arrival. A flight counts as on time here if it reached the gate at IAH less than 15 minutes behind schedule. Airport pages score departures instead, because that is the number you can act on when you pick a booking time.