IAH to SEA flight delays & on-time performance
Nonstop flights from George Bush Intercontinental Airport to Seattle–Tacoma International Airport · 1,874 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at IAH or SEA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Houston (IAH) to Seattle (SEA) arrived on time 79% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.4% were cancelled, and 6% arrived an hour or more late.
- Alaska Airlines was the most punctual airline here (80% on time); United Airlines was the least (78%).
- Departures scheduled around 6am did best (94% on time); around 7pm did worst (68%).
- Tuesday was the most reliable day to fly (83% on time) and Saturday the least (76%).
- The largest source of delay minutes was late-arriving aircraft (39%).
Which airline is most on time from IAH to SEA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Alaska Airlines | 80% | 0.6% | 11 min | 3.9% | 852 |
| United Airlines | 78% | 0.2% | 13 min | 6.7% | 1,238 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am94%161 flights
- 7am83%197 flights
- 8am87%197 flights
- 9am81%198 flights
- 10am81%186 flights
- 2pm85%114 flights
- 4pm81%319 flights
- 6pm69%173 flights
- 7pm68%409 flights
- 8pm74%117 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday79%0.7% cancelled
- Tuesday83%0.0% cancelled
- Wednesday79%0.4% cancelled
- Thursday82%0.3% cancelled
- Friday78%0.6% cancelled
- Saturday76%0.0% cancelled
- Sunday77%0.7% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft39%
- Airline (crew, maintenance, cleaning, fueling)29%
- Air traffic control & airport congestion26%
- Extreme weather5%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)63%
- Extreme weather38%
- Air traffic control & airport congestion0%
- Security0%
IAH to SEA: common questions
- How often are IAH to SEA flights on time?
- 79% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Houston to Seattle cancelled?
- 0.4% of scheduled flights were cancelled (8 of 2,090).
- How long are typical delays?
- Across all flights the average arrival delay was 12 min (early arrivals count as zero). Flights that were late arrived 53 min behind schedule on average, and 5.5% of flights were an hour or more late.
- How long is taxi time at IAH?
- Flights on this route spent 21 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to IAH — 82% on time
More flights from Houston
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: IAH → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.