PlainFlights

Route · SEA → IAH · 2020–2025 BTS data

Seattle to Houston

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to IAH (Seattle to Houston) ranks #1076 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

82%
On-time
+3 pts
vs US avg
62 min
Delay when late
10,723
Flights
#1076 of 4927
Corpus placement

Cancelled

1.7%

Best Month

Feb 2024 92%

Worst Month

Jul 2025 65%

Distance

1,874 mi

Carriers

4

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 168 42 0 0 AS,UA
Nov 2025 148 27 0 0 UA,AS
Oct 2025 176 31 1 0 AS,UA
Sep 2025 198 21 0 0 UA,AS
Aug 2025 228 70 3 1 UA,AS
Jul 2025 236 83 5 3 AS,UA
Jun 2025 228 79 5 4 AS,UA
May 2025 187 47 1 1 AS,UA
Apr 2025 150 31 0 3 UA,AS
Mar 2025 150 28 1 0 AS,UA
Feb 2025 112 17 0 0 AS,UA
Jan 2025 130 20 5 1 AS,UA
Dec 2024 155 31 1 1 AS,UA
Nov 2024 142 26 1 0 UA,AS
Oct 2024 168 15 0 0 UA,AS
Sep 2024 204 28 0 0 UA,AS
Aug 2024 233 57 4 1 AS,UA
Jul 2024 248 71 15 0 AS,UA
Jun 2024 213 55 1 0 AS,UA
May 2024 214 55 6 1 AS,UA
Apr 2024 163 34 0 0 AS,UA
Mar 2024 150 31 1 0 AS,UA
Feb 2024 116 9 1 0 AS,UA
Jan 2024 141 28 20 0 AS,DL,UA

SEA–IAH seasonal on-time pattern

Best: February (89.9%) · weakest: June (71.6%)

70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 81.1%

Strongest calendar month

February

89.9% on-time · ~114 flights/mo

Busiest calendar month

July

~185 flights/mo avg

Weakest calendar month

June

71.6% on-time · ~159 flights/mo

Cancellation Rate

1.7%

71 of 4,258 flights

Diversion Rate

0.4%

16 of 4,258 flights

Origin-hub reliability standing

Mid-pack among SEA departures

From SEA, this corridor sits with 63 other 75–85% on-time routes out of 89 tracked departures, not the hub's reliability leaders (25 at ≥85%) and not the softest ( 1 below 75%). Destination: Houston · fleet on-time rank #2373 of 4927.

What the Data Says About SEA to IAH

Bureau of Transportation Statistics records show Seattle to Houston (SEA to IAH) running a 82% on-time rate over 10,723 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 62.0 minutes. The 1,874-mile corridor is served by 4 carriers, and over the last 24 months 1.7% of 4,258 flights were cancelled, 0.4% diverted.

The monthly split is wide on this route: Feb 2024 posted the strongest performance at 92% on-time, while Jul 2025 came in at just 65% - a 27-point swing worth factoring into travel timing.

On the multi-year calendar, SEA–IAH peaks in February at 89.9% on-time while July carries the heaviest traffic (~185 flights per month) ; the softest month is June at 71.6%, a 18.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to IAH rank among US routes by traffic?
According to PlainFlights' route traffic ranking, SEA to IAH ranks #1076 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from SEA to IAH?
Flights from Seattle to Houston have a 82% on-time rate based on 10,723 flights. The average delay is 62.0 minutes. The best recent month was Feb 2024 with 92% on-time.
What is the cancellation rate for SEA to IAH?
Over the last 24 months, 1.7% of flights on this route were cancelled (71 of 4,258 flights) and 0.4% were diverted.
How far is the flight from SEA to IAH?
The flight distance from Seattle (SEA) to Houston (IAH) is approximately 1,874 miles. This route is served by 4 carriers.
When is the best time to fly from SEA to IAH?
The best recent month for on-time performance was Feb 2024 (92% on-time). The worst was Jul 2025 (65% on-time). Consider booking during months with historically better performance.

Airports on this route

Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Using SEA–IAH data

SEA–IAH runs 3 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SEA and IAH airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, February (89.9% on-time) beats June (71.6%) on this corridor. Seasonal chart
  • 4 other routes post a similar 82% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.