Houston (IAH) to Seattle (SEA)
Flight time
≈ 4h 33m
Bearing
318° NW
Houston (IAH) to Seattle (SEA) is 1,872 miles (3,013 km) as the crow flies — the great-circle baseline most distance-based mileage programs credit.
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What actually flies IAH–SEA
Filed traffic dataIn May 2026, United Airlines operated the most departures, one of 2 carriers flying nonstop IAH–SEA; the Boeing 737 MAX 9 was the most common aircraft at 31% of departures; flights ran 85% full.
Departures
365
May 2026
Seats
62,772
both directions
Passengers
53,566
both directions
Load factor
85.3%
RPM ÷ ASM
Who flies IAH–SEA?
United Airlines operated the most nonstop IAH–SEA departures in May 2026 (213), one of 2 carriers on the route.
- UA
213 departures · 36,022 seats
Share of departures58.4%83.8%
Load
- AS
152 departures · 26,750 seats
Share of departures41.6%87.4%
Load
What plane flies IAH–SEA?
In May 2026, the Boeing 737 MAX 9 flew 31% of IAH–SEA departures — more than any other aircraft type.
- Boeing 737 MAX 9
113 departures · 84.9% load
31.0% - Boeing 737-900ER
77 departures · 87.5% load
21.1% - Boeing 737-800
57 departures · 88.1% load
15.6% - Boeing 737-900
56 departures · 85.6% load
15.3% - Airbus A320
47 departures · 86.1% load
12.9% - Boeing 737 MAX 8
14 departures · 62.6% load
3.8% - Boeing 737-700
1 departures · 72.2% load
0.3%
How has IAH–SEA traffic changed?
Nonstop IAH–SEA departures fell from 443 in June 2025 to 365 in May 2026.
Monthly nonstop IAH–SEA traffic, trailing 12 months through May 2026. Bars scale to the busiest month; months with no filed service show as zero.
June 2025
443 departures · 65,828 passengers
88.0%
Load
July 2025
459 departures · 72,116 passengers
91.5%
Load
August 2025
451 departures · 67,781 passengers
88.4%
Load
September 2025
399 departures · 54,945 passengers
82.1%
Load
October 2025
354 departures · 49,675 passengers
83.4%
Load
November 2025
297 departures · 42,268 passengers
85.2%
Load
December 2025
339 departures · 48,114 passengers
84.8%
Load
January 2026
269 departures · 38,327 passengers
82.8%
Load
February 2026
224 departures · 32,992 passengers
87.5%
Load
March 2026
284 departures · 43,492 passengers
88.2%
Load
April 2026
300 departures · 45,302 passengers
87.0%
Load
May 2026
365 departures · 53,566 passengers
85.3%
Load
By direction
Each direction is filed separately — they rarely match.
IAH → SEA
90.2% full
183 departures · 28,474 passengers
SEA → IAH
80.4% full
182 departures · 25,092 passengers
Nonstop IAH–SEA traffic has been filed since 2025.
Source: US DOT BTS Form 41 T-100 Segment (All Carriers). Data through May 2026; filings from 2025. Public domain (US Government work).
The airports
Frequently asked
How far is Houston (IAH) from Seattle (SEA)?
IAH to SEA is 1,872 miles (3,013 km / 1,627 nautical miles) measured great-circle — the shortest path over the surface of the Earth.
How long is the flight from IAH to SEA?
A nonstop covers the 1,872-mile great-circle distance in roughly 4h 33m of block time, before winds. Actual schedules vary a few percent by direction and aircraft.
What plane flies IAH–SEA?
In May 2026, the Boeing 737 MAX 9 flew the largest share of departures (31.0%), followed by the Boeing 737-900ER (21.1%).
What mileage do I earn flying IAH–SEA?
Distance-based programs credit off the 1,872-mile great-circle figure, then apply your fare-class earning rate. Revenue-based programs credit off the fare instead.
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